How to clean stains on restroom floor in a restaurant?

I've had great luck with Lysol toilet bowl cleaner. It comes in a black squirt bottle. It removed stains that bleach would not remove in our bathroom. Super stubborn ones also had to use Mr. Clean Magic Eraser.

Awesome cleaner in the purple bottle from dollar tree works great. Spray well and let sit for awhile then scrub with brush.

Visit an Industrial Restaurant and Janitorial supply. They have many products to choose from. Who takes care of your janitorial needs? You ought to have a service.

You did say restroom FLOOR correct? Lowes also has a section of extra strong cleaning products in a small section in the isle with their regular cleaning products. Should be able to find help there. Good luck😄