Without hesitation, Meng Zhao immediately began gathering materials to prepare for the production.

First, the limestone brought from Hongnong County was placed in a furnace and fired at high temperature. During the firing process, the calcium carbonate was gradually decomposed, releasing carbon dioxide. At the same time, solidified calcium oxide was generated.

After about two hours of burning, the grayish-white limestone gradually turned white, forming quicklime.

Quicklime mixed with water becomes slaked lime, also known as calcium hydroxide, which has high alkalinity and can remove grease.

Meng Zhao soaked the pig hair that Fang Muyun had sent in a mixture of lime water to effectively remove the grease and odor from the pig hair.

The pig hairs from different parts of the body have different degrees of softness and hardness, and everyone has different preferences when brushing their teeth. After soaking overnight, Meng Zhao asked the two children to help group the pig hairs according to their degree of softness and hardness.

After the bristles were made, the next step was to choose the handle. Meng Zhao chose three options: wood, bamboo, and the most troublesome, cow bone.

First, boil the beef bones to remove the surface fat, then cut them into strips with a cleaver. After that, you can't use a cleaver anymore; you have to use a sharpener to shape them little by little into the desired shape. Finally, drill small holes in the handle head with a hand drill.

The repaired handle is boiled in filtered wood ash water to remove the fishy smell and grease from the beef bones.

Everything was ready, except for assembly. Without glue, Meng Zhao could only divide the pig bristles into clumps, tie them together with cotton thread, and then thread them into the holes in the handle.

It is necessary to ensure that the amount of pig hair is sufficient to fully fill the entire hole so that it will not become loose during use.

Meng Zhao made several toothbrushes with different levels of softness and hardness for each type of handle. Once they were finished, he gave them to other people to try.

Looking at the brush in her hand, Gu was somewhat troubled. "Zhaozhao, this thing is so big, are you going to put the whole thing in your mouth?"

Meng Zhao nodded, "Yes, Mother, even though it's much bigger than a willow branch, its bristles are soft and can reach more teeth, making it much more effective than a willow branch."

Considering the children's needs, Meng Zhao specially made smaller toothbrushes, handed one to each child, and then began to demonstrate the brushing technique.

"Place the toothbrush at an angle into your mouth and gently make circular motions with a slight tremor."

"When brushing your front teeth, brush vertically up and down to remove all the dirt from between your teeth." Meng Zhao slowed down her movements, emphasizing the steps of brushing her front teeth.

"When brushing your back teeth, be sure to brush the inside for a while longer, as this is where dirt is most likely to hide. If you don't clean it out soon, it will turn into tiny worms that we can't see and will hollow out your teeth."

After demonstrating, Meng Zhao asked everyone to try it out.

Wei Jinglan quickly mastered the technique, her hands trembling slightly as she focused on brushing each tooth thoroughly.

The three children learned it quite well.

They had just finished eating, and there was still food stuck in their teeth. Normally, they would have to pick it out bit by bit with a twig, but this time they didn't need to.

All you need to do is brush your mouth a few times with the brush, and each pig bristle will reach every corner of your mouth, so you don't have to bother picking your teeth anymore.

Shen Qingyu's eyes sparkled with joy. "Sister-in-law, this toothbrush feels so good! I'll never have to poke my mouth with tree branches again."

"Wow, it feels so good to brush my teeth, sister-in-law! I won't need you or Mom to nag me anymore. I'm going to brush my teeth every time I eat!" Shen Qingze said excitedly.

Looking at the toothbrush in her hand, Madam Gu sighed, "I never expected such a small item to be so effective. Why didn't anyone think of it before? Zhaozhao is so clever."

In fact, Meng Zhao didn't know if this thing had appeared before. After all, there are many social circles nowadays, and many good things only circulate in the upper circles. She doesn't go to many places, so maybe it's just that Meng Zhao herself hasn't seen it before.

On this sunny day, Meng Zhao picked out two ox bone toothbrushes of just the right firmness, put them in a wooden box, and took them out the door.

Before long, they arrived at Song Wanyin's house. Meng Zhao stepped forward and knocked on the door. Since she had been there a few times before, the gatekeeper recognized her. So, while sending someone to inform the maids in the inner courtyard, he led Meng Zhao to the front hall.

Before she could even sit down, she heard light footsteps. "Sister Zhao Zhao, you've finally arrived! You have no idea how long I've been waiting for you."

"Sister Wanyin, I'm so sorry. I encountered a lot of things on this trip, which delayed me for a while. I just got back a few days ago and came to find you after settling things at my shop."

Although the two had not seen each other for more than two months, their old friendship had not diminished at all, and they showed no signs of estrangement.

After exchanging greetings, Song Wanyin affectionately took Meng Zhao's hand and led him to her study.

Song Wanyin sat on the couch, her tone slightly coquettish. "One night, I was lying in bed preparing to rest when I suddenly had a brilliant idea. Worried that I would forget it the next day, I secretly went to the outer room to find a pen and ink to write it down."

At this point, she couldn't help but laugh. "I thought he was asleep, but it turns out he wasn't asleep at all. I was caught red-handed while I was writing. In the end, I couldn't hide the fact that I was writing storybooks."

Seeing the happy look on her face as she spoke, Meng Zhao teased, "It seems that Lord Wang has no objection to Sister Wanyin writing storybooks."

Song Wanyin nodded happily, "Yes, he not only didn't blame me, but also gave me a study room so that I wouldn't have to write secretly anymore. I can write without worry. Although I didn't want to ask for his permission to write stories, even if he didn't let me, I would still write. But seeing how supportive he is, I'm still very happy."

"Lord Wang is a true gentleman, unlike some scholars who secretly read storybooks while simultaneously despising them as low-class."

After saying that, she took out a booklet and said, "These past few days since I came back, I've been relying on Sister Wanyin's storybooks to pass the time in the evenings."

"You bought it?" Song Wanyin's eyes lit up when she saw the book title.

"When I was away, I went to bookstores several times but couldn't find it. As soon as I got back to Qingshi County, I went to bookstores and bought several copies. I also gave some to my family and friends. But don't worry, I didn't reveal who wrote this story."

Although she didn't think there was anything wrong with writing stories, Song Wanyin was a lady from a prestigious family and the wife of a county magistrate. If this matter got out, it would probably cause her trouble.

“I naturally trust Sister Zhao Zhao to do things, but it’s a pity that my storybook has been on the market for over a month, yet it hasn’t sold many copies.” Song Wanyin lowered her head slightly, her expression showing a hint of melancholy.

In fact, she had already asked at the bookstores several times, but very few people bought her stories. Because of this, she secretly went to many bookstores and bought a lot of them to hide. If it weren't for this, those bookstores would probably have taken her stories off the shelves completely.