I'm in the process of redecorating my bathroom and I've got white bath/shower tiles and the grout is horribly discoloured. I bought some 'Grout Reviver' but it's crap! It's in a bottle with a round sponge dispenser like shoe whitener, so most of what you use gets wasted anyway as it's all over the tiles.
You have to go over and over the grout several times, back and forth, back and forth and it eventually lightens it up a bit, but nowhere near what I was hoping for. And at this rate one bottle will only do a few tiles - nowhere near the whole lot. It would cost a fortune, even if the stuff was any good, which it isn't.
There surely must be a better way. Anyone know of any products or homemade solutions for whitening grout.