Here's the perfect YouTube clip to answer your question:
http://www.youtube.com/watch?v=vvF4yurWSc0
Nagant revolver with .30 suppressor. Neat project that fellow did.
Only a few suppressors really are "silencers"; most reduce the noise enough so that the shot doesn't sound like a shot, and that is good enough.
Bad Idea. Can't believe the CIA or anyone would try anything this stupid.