Mix a little cayenne pepper with some water, and spray your trash can with it. Dogs hate that smell and he'll keep away.
EDIT: Hmm, hot sauce didn't work? You could try going through a few different types of peppers to make sure there isn't one of them that he really hates. I've heard cayenne works the best. Also, Febreze makes a carpet spray that is supposed to get rid of pet odors. For some reason my basset HATES the smell of that stuff, so much that I can't use it in the house or she'll make a fuss, sneezing and shaking her head and stuff. The other Febrezes are fine with her, but just the Pet Odor one she hates. Maybe it has a deterent in it to keep dogs from going on that spot again? You could try that.
A trash can with a tightly sealed lid (like the ones you have to step on a pedal to open) might keep him out, even if it isn't marketed as "doggy proof."