You can use bleach to kill any mold on your rubber bath mats.
How to wash rubber bath mats in washing machine.
Place your bath mat in a washing machine with a few other soft items such as towels or washcloths these will serve as scrubbers in the washing process.
If you are treating for stain removal let washer fill with water before adding any additives other than laundry soap.
Place bathmats in the washing machine add laundry soap and use a gentle cold water setting.
If needed you can add baking soda for odor removal and borax to help disinfect bath mats.
Wash your bathroom rugs on the cold setting with a gentle laundry detergent.
Set the machine for a large load on the delicate cycle even if you re only washing the rug and a couple of towels.
About 1 2 cup per load.
No scrubbing no mess and a very clean bath mat.
Hang your mats outside to dry or tumble dry on the lowest setting.
Throw your rubber bath mat in the washing machine with a couple of bath towels and then add your normal laundry detergent.
You should never use heat when drying plastic or rubber backed bathmats because it can cause the backing to crack or even melt.
Place mats in the washer taking care not to overload your machine.
Fill the machine with.
Set the machine for a gentle hot cycle.
After the bath mat is done being washed just hang it up to air dry.
How to remove bath mat stains from bathtub.
In the bathtub combine 1 cup of bleach per 5 gallons of water then let the bath mat soak for a couple of hours before scrubbing it with a scrub brush.