Ok, maybe 'drain' was the wrong word, 'transfer' might be more accurate. Please take a minute to consider this experience I had.
A friend had a TT that had three relatively flat aluminum cones that served as feet. The flat side makes contact with the flat bottom of the turntable. The turntable sits an a welded target stand. He put on a classical lp and during a loud passage that had a lot of bass the cartridge mistracked. He said, "that never happened before". I checked the cone footers and found that he had absentmindedly put them facing up, not down. We flipped them over and replayed the passage. Of course the tracking problems were gone. You could feel with your fingers a huge difference when you touched the TT base. We removed the cones and placed the TT on a folded over towel and tried it again. We could feel more vibration in the TT base than when the cones were under it (correctly).
This (unscientific) experiment suggests to me that the cones do more than isolate the TT base, they 'transfer' the 'airborn' vibration that the base was picking up from the music to the target stand. After seeing that the TT would mistrack when the cones were upside down, and not when the TT sat on a towel, it would be hard to argue that the cones were not 'transfering' energy from the stand to the TT base.
I dont understand why it is so hard to imagine that it is possible for vibration to be transfered from one object to another. If its just 'isolation' thats taking place, where does the energy go?