I'm considering placing a sign on the wall saying to knock for eggs next time we want to get rid of some. I think that's a fair compromise.

We get a lot of crime around here... The issue with an eggs honesty box is that it's likely to be a nuisance to the neighbourhood. If people are willing to smash windows, I doubt they'd think twice about throw some eggs around. In fact we got egged ourselves a couple of halloween's ago...