It's best to solve the tin can in a day or two. Don't touch it with dirt. Remember to cover it, and you'd better coat it with plastic wrap.

When digging with a spoon, remember to wipe it with a clean paper towel. This thing is rich in nutrition, and it is particularly easy to breed bacteria. If you are not careful, it will go moldy and deteriorate.

Anyway, I remember one time I didn't dry the clean water. I put it in the refrigerator for two weeks, and it broke when I opened it. Usually it lasts at least a month.

Toothpaste can be packed for about a week. After all, the lid is tight, and it is not easy to be contaminated with too many bacteria because it is not a spoon or something.