On Wed, 31 Jan 2018 10:34:16 -0800 (PST),
wrote:

i need to clean my toilet to flush better,it also has a water saver ring ,good for the pocket but not the flushing anymore.i was considering trying clr but am wondering about the muriatic and hydrochloric acids.i'll probably have to worry about replacing fill valve and seals afterward but am more concerned about the fumes..what do you think?

See step 3 regarding acid: Using Muriatic (Hydrochloric) Acid

https://www.wikihow.com/Fix-a-Slow-Toilet

If you have a septic system; neutralize the acid, before you flush the
bowl. (baking soda)