Problem with Nuvi suction cup falling off, solved

I read on several forums about the suction cup that comes with the Nuvi
dash/windshield mount falling off. I tried my new Nuvi and, yes, it
fell off. My solution was to put a thin smooth coat of silicon grease
around the outer 3/8 in or so of the suction cup. I choose the pure
type that is used on plumbing fixtures because it was less likely to
contain some impurity that could harm the synthetic rubber. I figured
that if a little in my drinking water didn't hurt me it wouldn't hurt
the rubber. I pushed it down tight and flipped the little lever. Oh,
yes, I cleaned both surfaces with some acetone prior. Alcohol should
work as well.
Bob