We have a bathmat that we use to line the tub when we bathe our daughter. After the bath, we remove the mat and suction it to the shower wall (which is some sort of frosted glass)

I've noticed black mold growing on the suction cups.

I tried to use vinegar...sprayed it and tried to wipe off the mold. I tried a little bleach too.

Nothing seems to remove it.

Is there something else I should try?