Silicone Grease source

[Xylene]

The glass-to-glass connections of vacuum desiccators, taper fit glassware, and all-glass stop-cocks require a very thin film of silicone grease. This easily applied using the wide flat end of a tooth-pick as a spatula. Pure silicone grease is often hard to obtain in remote cities, but it is used by automotive electricians on bulb sockets and battery contacts.
NOTE: stop-cocks with a Teflon valve core do not require such lubrication.

The one I'm using is PERMATEX "dielectric tune-up grease" part # 22058 it's a 85 gram tube

AGS in Muskegon MI has also has a version: "AGS Dielectric Silicone Compound" part # DS-1 it's a 35.5 gram tube.

[LittleJimmy]

Under the Tri-Flow brand name Sherwin-Williams Co. offers

High Performance Synthetic Grease
Tri-Flow High Performance Synthetic Grease is specially formulated to lubricate any surface that slides, glides, rolls, twists, turns or spins. This non-melting, waterproof formula is designed to seal out water and contaminates and prevent rust and corrosion under extreme temperatures (110 to 400F). This pure synthetic grease is fully compatible with most rubbers and plastics. It is available in a squeeze tube that fits most injection systems.

I know it doesn't say it is pure silicone grease, and the msds sheet didn't add any clarification. I've used it in other applications; it is a slightly opaque clear grease.

I was wondering if dry Teflon (PTFE) lubricants might also work in this application. There are a few companies that make spray dry lube. Many gun shops carry these products, as do many hardware-type stores.