Regular SuperLube synthetic grease is NOT Silicone based. In the
Technical Data Sheet (linked here, and attached) it states
'There is no Silicone in Super Lube® Multi-Purpose Grease with Syncolon® (PTFE)'.
There is also a
compatibility chart (also linked and attached) which indicates that the compatibility is 'Excellent' with Nitrile (aka Buna-N) and Neoprene, but only 'Good' with silicone. So perhaps there is an ingredient which is less than ideal for silicone, I'm not sure what to make of that.
Note that Super Lube makes multiple types of grease, including a silicone grease (which of course is
NOT compatible with silicone). But their synthetic grease, which is their most common / standard product, is not silicone based.