Could give this a try: Tub Cleaner - vinegar and dish soap, no scrubbing! Heat 1/2 cup white vinegar in microwave for 90 sec, pour into spray bottle. Add 1/2 cup BLUE Dawn dish soap. Shake gently to mix. Spray on surface, let it sit 1-2 hours. Just wipe it away then rinse with water. Should also take soap scum off shower doors!
Heavy duty floor cleaner recipe… ONLY use this and it leaves floor spotless. (Heavy duty floor cleaner recipe: 1 cup white vinegar, 1 tablespoon liquid dish soap, 1 cup baking soda, 2 gallons tap water, very warm.) It leaves everything smelling amazing.