I let them eat a few pieces last night. Today, my 7 and 4 year old are eating 7 and 4 pieces respectively (a piece for each year). Mostly, we only went to about 20 houses, so if they eat everything it's not a big deal. We regulate how much is collected and it's much easier!
Today, we laid all the candy out and basically strongly suggested they give a few pieces to the adults...teaching them sharing and getting a few treats!

In the end, it will be about 30 pieces of candy total. Not too bad, and they'll probably forget about it in a few days.