See: Corner Speed RC 

Coming from Corner Speed RC is a premium lubricating grease. The grease has been carefully formulated to create dynamic lubrication between o-rings and metal parts and it was specially designed for use on rubber components and gaskets such as shock/diff o-rings to allow smoother operation as well as minimising leakage. Unlike other silicone-based grease which slightly swells the O-rings and rubber parts, Corner Speed RC O-ring grease is a clay-based grease which is well known being more gentle on the rubber parts for more consistent operation.