Thermostat gasket leaking AGAIN!!!!

I haven't read all the posts, but here is my experience. The ONLY gasket I use is silicon....& never have a leak.

Smooth surfaces like chrome are difficult to seal, no matter what you use. If you use chrome, use coarse sandpaper & sand off the chrome to leave a rough surface.
Using a Dremel with a small carbide tip, I ground a small channel into the gasket surface, on the intake flange & t/stat housing. About 0.020" deep, not critical. This provides an 'anchor' for the silicon.