Any suggestions for best non-slip tub mats and are suction grab bars safe?

I have some little yellow ducks made of rubber with a suction cup under each one to prevent slipping down in the shower or tub. They can be arranged in a pattern that is most comfortable for the bather.

I had bars in the tub when we moved into our house. One of the bars lay in the bottom of the tub with broken tiles on the wall and scattered in the tub. I’d say no safety bar is sturdy unless it’s bolted to the lumber in the inner wall. So if I was wanting one I’d have it installed Professionally.