I meant to add to Best Bubby – if you cannot get Tilex (brand) can you get a solution of Sodium Hypochlorite? That is what Tilex basically is. It is a MUCH stronger form of regular chlorine bleach. I have found it to be invaluable in removing really stubborn stains from fabric safe/color safe items. I have used it to spot clean a white tablecloth from wine stains that were already set-in. You have to be careful, as some “whites” really are not white, they are white-colored and the bleach actually discolors them. But if I tried to clean something and nothing helped, I would be inclined to get rid of it, so the Tilex is always a last-ditch effort on such an item, and I have saved many of my husbands shirts that way. (I once left an entire load of white shirts in the laundry, damp, because it was erev yom tov and I forgot to dry them before bensching licht. By the time I was doing another laundry MANY days later, and discovered the wet shirts, they were so full of mold and mildew I was going to throw them out. I tried regular clorox, but it didn’t remove the black spots. Then I got the brilliant idea to try the Tilex on them. If it worked on the tiles, why not on the shirts? I sprayed each spot individually and it was amazing, B”H.
As with any bleach product keep it separate from the ammonia bottles.