I installed 2 suction cup based grab / assist handles in out fifth wheel's shower.
Wife is a little unstable and needs the extra help.
Attached to the glass panels rather than the flexible plastic enclosure.
They have been in more than two years and hold well.
Be sure to really clean the glass before installing.
2007 Tango 2660RKS Fifth Wheel, 2006 Chevy D/A 3500 with service body,