Not very practical
It is required to actually record and justify child work. For normal work, it is very hard to justify a pay better than $10/hr. And it is very difficult to record more than 1 hour per day. So really not much to offset.
One exception someone posted here a while back: his high school child developed some iPhone applications and made a decent six-digit figure, more than what he earned himself. But that is not hiring children anymore.
Sent from my iPad