We have a rule in our house: You can eat all the candy you want on Halloween, and the next day it goes away.
For my kids, this is not a problem, since they rarely eat candy. It certainly isn't off limits, but we don't buy it to have in the house. They eat and get sick, eat and get sick...until bed. In the morning, they have sugar hangovers and happily get rid of the candy.
If you like the idea of ditching the excess candy, check this out:
This site lets you search for a dentist in your area, that will *Buy*, or trade your child's candy for some sort of treat. They then send the candy to the troops! How cool is that?