Thanks all. Pumice does work - I just needed to know that it wouldn’t harm the porcelain. Amazon has a nice one on a stick, looks like an ice cream pop, and it has a string loop so I can keep it hanging from the toilet’s water shut off.
I have to say - it’s really nice to see so many responses from familiar old fools whose posts I’ve been reading for so many years, some for over two decades! I used to spend a lot of time every day reading posts on TMF and now when I go to my list of favorite boards I often see a string of 0 posts. Rest assured - if you keep posting, I’ll keep reading!
Trini