Advanced Hard Water Stain Remover or Professional Tile Cleaning Service.

The user has tried common household solutions (Dawn, Lime Away) and physical scrubbing without success, indicating a need for a more potent product specifically designed for extremely stubborn hard water stains, possibly with a different chemical composition or application method. Alternatively, a specialized cleaning service that guarantees removal of such stains would also address this pain point, especially since the user is 'at a loss' and doesn't want to 'waste more money buying supplies.'