I'm not sure the word 'drain' is properly used to describe what happens when internal circuit microphonics are reduced through various processes. it's more reducing outside resonance effects.
Actually, one of my preferred analogies is to use a bath tub with the water faucet on full. The tub is the chassis and the water is the energy and my goal is to create a drain so large as to not allow for any opportunity of bottlenecking the water from draining. If bottlenecking begins, it's game over and the system ends up sounding not too dissimilar than so many others.
That's why a superior mechanical conduit must be created to allow mechanical energy to more freely travel between normally disparate objects by making the objects as congruent as possible.
But then again, if isolation was a valid methodology and floor-borne vibrations were a concern, maybe the water is really coming up out of the drain and exiting into the faucet.