Might be a coinkydink, but when I changed our Amazon over to silicon some years back, I had a series of immediate failures of the switch. They'd last days or weeks, not years. I never made any sense out of it.

That car now has one of Ron's mechanical switches in it.

OTOH, I've never once had that switch go out in a VW, and that's a few hunnert thousand miles in three different ones over 28 years now. I've had regular failures in Volvos no matter what fluid I was using, although the silicon seemed like the real kiss of death.