Cannabis is a wind pollinator, so the odds of pollinating a crop that isn't very close is pretty low. And even if you do, it'd only be a few seeds if that. If you plant all your seeds in very visible locations, they'll probably all be discovered well before the males can flower, especially if you plant them early in the year.

I think it's a neat idea, although it'd be best to do it kind of far away from anywhere you plan on growing.