Silicone Grease Question

I have read that silicone grease is helpful when installing tight rubber bushings. Is that the same thing as lithium (white) grease? Is there something else that will help ease the installation? I know that petroleum based products can be harmful to rubber.

I can't seem to locate "silicone grease" at the local parts dealers. They look at me like I'm crazy. Have all my new suspension parts in hand and need the right lubricant so that I can do the work this weekend.

Nic
'85 300CD