I don't remember if he was talking about the snail or dogbone or lower, and I actually haven't looked that close at any of them on Il Mela to see if he did them.
I do remember Mark talking about it, the RTV in the voids stiffened up the mount and covering it kept oil from weakening the rubber.
Years ago I did repair a dogbone on blackX that had severely cracked and deformed rubber with Shoe Goo. That worked out quite well, it stopped the motor from making a bad "clunk" getting on and off the throttle.