As above, it's virtually impossible to "silence" a revolver, notwithstanding the idiotic nonsense we've seen a million times on teeeeveeee and in the flicks.
Silencers, or "sound suppressors," are legal in states which have not forbidden them, (Class III states), but you have to register with the Federal BATF, pay the license fee, etc, in accordance with the N.F.A.
Idaho is a Class III state, and I know several guys who have gone through all the trouble to own them. They use them on their submachine guns (also Class III.)
FWIW.