We have perfectly fine old toilet, which works fine and has no
mechanical problems. I care for my mom, who suffers from dementia,
and when she uses the toilet during the night, more often than not, she
forgets to flush. This leaves her urine to sit and deposit/stain
until I wake next morning to make sure the commode is flushed. Over
time, this has caused heavy brown deposits (lime?) in the bottom of
our porcelain crapper. I've tried to keep up, but they jes keep
adding up and now even scrubbing with the new fangled hi-tech brushes
with disposable pads can't remove the most heavy stains. I tried some
Lime-Away, which cleaned up the lighter deposits, but the heavy darker
one's in the very bottom remain. Any suggestions on what might remove
these stains? Would muriatic acid be too much? Obviously, I don't
wanna destroy the smooth porcelain glaze.

If you are on a septic system, I would try other alternatives before
dumping acids or other caustic chemicals down your toilet. You wouldn't
want to cause problems with your septic system just to remove a stain.

Dark stains are usually a build up of rust or minerals. I have removed
heavy stains like that using a mild abrasive like Comet or Ajax and one of
those green nylon scrubbing pads. Yes, you have to stick your hands in the
toilet and do some scrubbing, but it has always worked for me. There's
enough abrasive to remove the stain, but not enough to damage the finish on
the toilet. It helps to turn off the water to the toilet and flush as much
water as you can from the bowl. Scoop out as much of the remaining water as
you can before scrubbing.

I have also had good results with a product called CLR (Calcium/Lime/Rust).
It's fairly harmless, but it can damage some surfaces like laminate counter
tops. I once left a permanent ring on our old countertop when a little was
on the bottom of the dish I was using to hold it while cleaning.

Anthony Watson
Mountain Software
www.mountain-software.com/about.htm