Baking challah and children

[Yehudis]

I cheated. I made challah dough at night, when the children were going to sleep. I was almost found out -- my 3 y.o. came out of the bedroom, saw me mixing something, and said excitedly, "I want to help!" I said, "No, it's sleep time." She was very disappointed. I told her she could help me shape the challos in the morning.

I find that when I make challah dough together with the children, clean up takes a lot longer than the dough. Everything becomes covered with flour or wet dough, including the children themselves that need a bath afterwards. Any advice on how to minimize the clean up?