In article , (marc) wrote:
My new home has textured Formica in the bathrooms that shows all the
watermarks and is very difficult to clean. I have tried all the
baking soda-and cleaner type cures but the stains are just too
stubborn.

Try white vinegar instead.

Question: Is there a product I could coat the Formica with to seal it
and make the surface more cleanable? Or should I simply tile over
the Formica?

Clean it thoroughly, then wax it. Any automotive wax should do fine. That'll
make it a lot easier to clean in the future.

Also, consider getting a water softener.