Cover for Squeezebox Radio Knobs

I still use my old Logitech Squeezebox Internet Radio in my kitchen. This is a rather old radio (I think I bought mine in 2010), but still working perfect for my needs.
This is the device I am talking about: https://wiki.slimdevices.com/index.php/Squeezebox_Radio.html
The only thing I bother about is the rubberlike-soft-coating on the two turning knobs. The rubber got so sticky on the surface, this is really disgusting. I tried to remove the coating with different solvents, but without success.
So I made two super simple covers which simply get pushed on the knobs (they will keep in place by their size and the sticky surface they cover...)
Print them in TPU and you have a rubber-like feeling again without the icky stickyness.