CLR Kitchen and Bath...comes in a yellow spray bottle...I love this stuff it works great..spray it on...leave it for a bit and wipe off...

Awesome Orange is awesome. Love it!!!

This sounds like it would work on our stall shower walls. Shower was installed in 2nd bathroom about 40 years ago and in recent years I could never get all of the soap scum off the walls. Found replacement shower unit online but drawback was the most who bought them left bad reviews. Mostly the shower pan cracked and leaked water into the downstairs rooms. Guess the quality of the unit declined over the years. We're left with the choice of having a new shower hand built or trying to get the old one clean to my liking. Can't hurt to try Krud Killer or use one of the other recommended treatments than paying big bucks for a hand built shower stall. May in Jersey

Kaboom is what I use

same here , but use ordinary malt vinegar instead -------v cheap, v effective.

I use the Kaboom spray that goes on blue and turns white when its done. Works every time

Question: regarding white vinegar -- It's the mineral ring around the waterline in the toilets that drives me crazy. No amount of scrubbing fazes it. I've tried every product I know of BUT haven't tried white vinegar as suggested here.
Would I just pour some into the water? and let it 'soak'?
Any suggestions would be welcomed. Thanks in advance.

I know what your talking about, had an old house here in Edmonton and tried everything to get the mineral build up off. Vinegar didn't work. Had a swimming pool in this house and every year drained and scrubbed it down with muriatic acid. It removed all stains from the wall and floor of pool. This acid is also used for cleaning off newly installed ceramic tiles.
I would put about 1/4 to 1/2 cup in the toiled let sit for 20 min and presto buildup gone. Just remember very toxic, use gloves!! stand back from toilet so you don't get any fumes, if you have a window in your bathroom open it, mine didn't and had no problem. You can get the acid at most home hardware stores. Hope this heps and good luck. Dar

I did this very thing to my Grandpa's toilet. It had so much build up in it there was no removing it without chiping away at it. I used Muriatic acid and it made it look like a new toilet. I drained all the water out of it then used paper towels to dry up all the moisture then poured the acid in. Boy did it boil. I had the window open above it so all was well but you have to be really careful with that stuff.