If the pesticide you used was rated for use on consumables, like vegetables, then you don't need to wash it off of the buds. In fact, spraying the buds with water could invite mold, and would render the buds practically useless.

I believe a lot of pesticides used for vegetables are just insecticidal soaps that degrade over time and are not harmful to those that consume it. It might have a bit of a funky taste, but that's better than a bud that can't be smoked because it's riddled by mold.