I quit using silicone / RTV based products for some applications as they need clean, non-oily surfaces surfaces to bond well, which is impossible in some applications. In ye olden days I might use a dark, gooey gasket compound after trying to degrease surfaces, but so far have found that teflon paste work fine as a replacement for smaller jobs at least. It has a wider temp range than most of the other auto products, that's why Permatex calls their product a 'high temp sealant, it appears to more inert than other auto producte, and seems to be used in a wide range of industrial applications.
Typical silicone adhesive outgas acetic acid, who knows what the other products outgas, so I'm not worried about something that seems to be rated for a wider range of applications.
Something else that I try to do is to make sure that both surfaces of an assembly are flat, free of nicks, high spots, etc., and I'll either lightly refinish the surface using a fine wet/dry on a fla tsurface, or use a flat sharpening stone, or worst case will use a mill file. The thin layer of teflon paste on the gasket is just to help seal. The paste seems to be recommended for lots of tapered threads for obvious reasons.
Here's the stuff I currently have, a plumber's teflon paste. Use an auto or aviation product if worried.
http://www.wmharvey.com/prod/cat2/ptc/tfe.php
TFE Paste is a pure white thread lubricant and sealant made with PTFE. Brushable paste dries slowly, is non-hardening and withstands up to 3,000 PSI on gases at temps from -50°F. to +500°F. Use on water, steam, natural & LP gas, oils, fuels, dilute acids. Apply to metals, PVC, CPVC, ABS, polypropylene and nylon. TFE Paste is our BEST all-purpose sealant for HEAVY DUTY applications. UPC and NSFlisted.