Mould often appears in grout lines due to their porous nature, especially in humid areas with poor airflow. Black, brown, and yellow stains recently marred my bathroom tiles, making the space look unclean despite deep cleaning. Natural remedies like white vinegar and baking soda failed, so I tested three popular mould removers on separate grout sections: Astonish Mould Blast Stain Remover, HG Mould Spray, and Mould Magic gel.
Products Tested
Astonish Mould Remover costs £1.99 at Wilko and The Range or £2.99 at Lakeland. HG Mould Remover sells for £4.29 at Savers or £6 at B&Q. Mould Magic, a gel from Must Have Ideas, comes in two tubes for £12.99 and promises complete mould elimination in one application.
Testing Process
I wore gloves and dried the areas first to avoid dilution. The mould varied from black and brown near the shower to yellow spots elsewhere.
Mould Magic Gel
This thick gel applies smoothly, stays put without dripping, and has a mild scent. It requires 2-3 hours to work, suitable for those who can wait.
HG Mould Spray
The foamy spray clings well to grout, though some runs down tiles. Bubbles adhere effectively. Leave it for 30 minutes; the strong bleach-like odour fades with ventilation.
Astonish Mould Spray
The watery formula runs quickly but works in 10 minutes for tough stains. Its scent is noticeable but milder than HG’s.
Results After Wiping
Astonish surprised: one wipe with a damp cloth removed all mould, leaving grout mostly clean. A quick rinse enhanced results.
HG performed excellently—the mould dissolved visibly before wiping. Grout emerged bright white, a standout feature.
Mould Magic erased the mould fully but left gel residue on tiles, requiring extra effort to rinse away.
Final Verdict
All three effectively tackle grout mould. HG Mould Spray wins for its 30-minute action, superior whitening, and easy availability. Astonish offers quick, budget-friendly results but penetrates less deeply. Mould Magic excels on silicone sealant yet takes longer, leaves residue, and is harder to source.

