Let me guess !! Silicone in the bushing, for example Engine Mouth have rubber bushing but not solid. It's has hole in it, so it can absorb the vibration. Now fill all that hole with harder silicone will limit the movement of the engine mouth.
Many people here to it to their car to make bushing a little stiffer. Warning you can not fill it all at one time. Because silicone is hard to dry you have to fill a little let it dry then do it again in many layer. More importance what kind of silicone? There are so many difference type! ???
Im I guess right? ???