My shower does not have a hook to hang my loofah, so I came up with an alternate solution that builds on the existing handrails (I could not be bothered to buy a suction cup). Basically there are 2 semicircular collars that are held together with nuts and bolts to clamp around the rail. Friction prevents the collar from slipping when the loofah is hung on the hook, ultimately giving it a way to dry out without water going over the handle.

Nuts and bolts are size 6-32 with 1" length.
Rail is 1.25" in diameter.

I printed without supports