Other matters which begin to apply thirty days before Pesach?
- It is proper to beware from using Chametz in a way that will be difficult to remove on Erev Pesach.
Giving children play dough within thirty days before Pesach:
Many varieties of Play dough are made of actual Chametz.The company brand Play-doh, which is the main manufacturer of the item, makes the compound from flour, water, and food coloring. Therefore, in compliance with the above law, it is suggested that children not be given play-doh to play with, starting from Purim and onwards. There are alternative brands of Play-dough that do not contain Chametz, and thus would not pose a problem in their use over [Chol Hamoed] Pesach.
- One is to be careful that crumbs do not fall into Sefarim beginning from Purim and onwards.
- One is not to starch ones clothing or tablecloths with Chametz starch.
- Buying Haggadahs: One is to buy a personal Haggadah for each of his children. The Haggadahs are to contain pictures and designs in order to arouse the interest of the child.
- Buying Pesach vessels: One is to buy nice Keilim for Pesach.
 Admur 436/23
 Play dough can be made in a variety of ways. Most Play-doughs on the market consist of flour and water. Home-made recipes will include salt, flour or corn starch, a vegetable, canola, or olive oil and cream of tartar. Nevertheless there are some companies that make it from other non-chametz ingredients. Such non-Chametz play doughs are commonly called Plasticine [Plastalina in Hebrew] or silly putty. One is to verify the brand that is being used and the ingredients they use to make their dough. Nevertheless most play dough that uses real flour will feel softer than regular silly putty or Plastelina and can hence be told apart.
Must play-doh be destroyed before Pesach even though it is not edible? Play-doh is consumable and does not contain any poisons or dangerous material for a human. It thus must be destroyed just like a piece of actual dough. It does not follow the allowance of owning Chametz that is not food, which is brought in 422/22, as there it is referring to Taaruvos Chametz while here it is Chametz Beiyn. Nevertheless perhaps it should be viewed as Chametz Nuksha being that it is not meant to be eaten, and is hence exactly similar to the dough made by the Sofrim, mentioned in 442/20, which is Chametz Nuksha. Thus although it must be destroyed or sold to the gentile before Pesach, if one did not do so and found play-doh on Pesach, it is be destroyed without a blessing as is the law by Chametz Nuksha in 442/20.
 Aruch Hashulchan 436/15
 Sichas Purim 1987 brought in Otzer Minhagei Chabad Purim 238