Deep-Clean Floor Grout With Toilet Bowl Cleaner

The Problem

Floor grout collects years of ground-in dirt that mopping never touches — the floor gets "clean" and the grout lines stay gray. Dedicated grout cleaners exist, but the bottle already under the bathroom sink is built for the same job: clinging to a surface and dissolving mineral-bound grime.

The Technique

1. Squeeze a bead of toilet bowl cleaner along the grout lines — the angled bottle neck makes it easy to run a controlled line. For a full floor, do the whole thing in a pass.
2. Let it sit 20 to 30 minutes. Little bubbles forming on the lines mean it's working.
3. Scrub the lines with a stiff brush. Hit the tile faces too while you're down there — they're dirtier than they look.
4. Mop the whole floor thoroughly to pick up the loosened grime and rinse away the cleaner. Wet spots dry patchy; judge the result the next day.

Once a year keeps it at reset level.