Muriatic Acid Tidbits.....

For most of my life I bought toilet bowl cleaner i cardboard cylinders with plastic insert caps. Then I bought more than I needed, and the last container say under the bathroom sink for years. When I finally noticed it, the paper was bubbling and the electric heater under the same sink had pits in the chrome. It was really a shame because it was the heater my parents bought when I was born, to warm the bathroom before bathing me. It was in perfect condition before, even the cloth cord, at age 60 or so. It has an on/off switch operated by stepping on it. The heater still works fine, and I cleaned the pitting up a lot with rubbing compound, but it's not the same anymore.

Do they still sell toilet bowl cleaner in cardboard containers?

I would not use muriatic acid anywhere inside the house. The only use I have for it is to soak the 'fingers' of my inground pool filter or use it as a herbicide to kill grass and weeds around the pool and other concrete walks. (I have a 4' wide concrete walk around the pool and then a 3' wide loose stone area to the security fencing)

It's rare to find any liquids sold in cardboard containers anymore.

Ever go into a grocery store?

They were solid, like small gravel, crysltals maybe, but not liquid.

Liquid toilet bowl cleaner is relatively new.