You mean a hammer de-bouncer? I have one in my 2250XT and my 2240. They work. It gets the shot count up a bit and it quiets the report some.
They're not a "Store Bought" jobbies though. It's just a piece of ice maker tubing with a piece cut cut out so that it can close in around the hammer pin and fit in the cocking slot. The open side faces the rear of the gun. Doesn't provide much drag on the forward stroke of the hammer, but it butterflies open during the hammer bounce event and stops it.
The one's I've seen are nice white nylon pieces with an S cut in them. But from what I can see, they do the same thing.