No kidding, I want to beat the dawg snot out of whoever started the toilet bowl cleaner rumor! I was a Merchant Seaman for 16 yrs and had a Capt. order me to use it as a rust buster. Long story but I got logged for it, lol.
Don't use it. Does nothing and makes smoke with some chemicals/paints. I don't think they are in any way safe and part of why the fight I got logged for started, lol.
My personal all around favorite penetrating oil is "3-in-1" "Marvel" is also awesome but am sure folks will join in and offer other thoughts.
Any good, name brand penetrating oil should do what you want and get it functional. Might take a day or 2. But no rush, your making functional art!
Just how I use it and do some thing like this, put some in/on so that it drips in and on. Let it sit for a good while. Then try with no great force to "wiggle" it. Then add some more and again, gently wiggle it.
Not advice, just what I do.