What's the best way to get out a ring in the toilet that won't budge?

Get a large bottle of Coca Cola and pour it in and leave it for a few hours then scrub with toilet brush and flush. If the ring is really bad you might need to get a pumice stick.

Adamsiam, when you poured in the Clorox, did you use Clorox bleach, not cleanser? Did you add enough bleach to raise the water level above the stain? Did you leave it overnight? When you scrubbed the next day, did you flush, then scrub with Clorox or another cleanser? When you tried Coca-Cola, was it fresh (not flat), and did you give it time to work befor scrubbing? If you followed all these parts, you need to buy an industrial toilet bowl cleaner, sold at Sam’s Warehouse, Office Depot, or plumbing supply place. If you have a plumber with an office near you, you may find these products sold in the office. Some Walmarts and Targets carry these products in or near the hardware departments. ☺️

Office Depot?? Did you mean Home Depot?

Use a pumice scrubber, always with wetting the stone first, ONLY o a ceramic/porcelain bowl. It will scratch anything else.

Yes, a pumice stone. Be sure to soak the stone first, then just rub it back and forth on the ring. It may take a little time, so don't be discouraged, just keep at it.

Use a pumice stone.

I remove water from bowl just dip it out with disposable cup below stained area,then use pumice stone to scrub away stain,flush and clean as usual.Pumice stone can be found at most dollar stores,Walmart or where cleaning supplies are found,Good luck!