Dad's bath mat is probably doing its job right up to the day it fails. The suction cups hold while the surface is clean and dry, then stop holding with no warning. A slip at the tub edge is the kind of fall that never gets written down, so the mat needs an owner and a plan.
Local option: New Plan Care gives families in the St. Louis area in-home help so a parent can stay home: companionship, help with bathing and dressing, meals, and overnight care. Call (314) 405-0887.
What the cups need
Suction holds on a smooth, clean, dry surface. Soap film, body oil, and mineral scale build up on the cups and on the tub floor, and that film is what breaks the seal. Rinse both with warm water and a mild soap, then dry them fully. Skip oily cleaners on the tub floor, because they leave a residue the cups cannot grip.
The three-part check
Press each cup flat with your hand, then lift a corner. If a cup lifts easily after a clean surface, that cup is finished. Turn the mat over and look at the underside for flattening, cracks, or a dry, chalky edge on the cups. Lay the mat flat and check that no edge curls up, because a curled edge is a catch point for a foot.
Replace on a trigger, not a feeling
Decide the replacement point now, while nobody is arguing about it. A good trigger is any cup that fails after a full clean, any crack in the backing, or any curl that does not flatten. Keep a spare in the linen closet so a failed mat does not turn into a week without one. Write the trigger on the inside of the bathroom door so the check does not depend on memory.
Name one checker
Put one person in charge of checking the mat on each visit. The check takes less than a minute, and it only works if somebody actually does it. Next move: clean the tub floor and the mat tonight, press each cup, and write the cups that fail on a card taped inside the bathroom door.