Recommended Tools: Use a stiff-bristled scrub brush or an old toothbrush to effectively reach into the grout lines. For minimizing manual effort during a deep clean, an electric toothbrush can be highly effective.
Tools to Avoid: Avoid using abrasive tools like steel wool or harsh scouring pads, as these can damage both the tiles and the grout. Also, avoid using straight bleach or ammonia-based cleaners, as they can weaken and erode the grout over time.
For a comprehensive list of recommended and non-recommended tools, check out the Amenify blog post: How to Clean Shower Grout?
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