[glynnw]

This worked for me.  Put one in front of each speaker and sweet kitty soon learns to leave them alone.  It just shoots out a puff of air and scares kitty away.

https://store.petsafe.net/ssscat-spray-pet-deterrent

[NINaudio]

I have one of those rug pads (for use for rugs) and they do work well. The only reason I pointed out the other material that needs gluing is because that type of rug pad has even higher resistance to slipping. The material you linked to would probably do the trick.

I also wonder if putting a bit of felt or sponge soaked in a cat repellant made from essential oils and spices on top of the glass would help discourage the behavior?

I've got this to put on top of the glass:

https://www.amazon.com/gp/product/B0813YTNCF/ref=ox_sc_act_title_2?smid=A1DHDOITQNJY67&psc=1

[NINaudio]

This worked for me.  Put one in front of each speaker and sweet kitty soon learns to leave them alone.  It just shoots out a puff of air and scares kitty away.

https://store.petsafe.net/ssscat-spray-pet-deterrent

Yes, we've got two of those cans.  It doesn't deter one of our cats from much of anything.   

[jsalk]

@Photon46, it looks like this may be perfect and no gluing needed:

https://www.rugpadusa.com/collections/natural-rubber/products/super-lock-natural

I have used this same material, but in black.

It is sold as a "non-slip router mat" at rockler.com.  But I have seen it sold as shelf liner at Home Depot and as dinner place mats at Bed Bath and Beyond.  Nice stuff.

- Jim

[NINaudio]

I had originally purchased some shelf liner to use, but upon reading what it was made from I discovered that it does use plasticizers in it's manufacture. I therefore opted out of going with it because I'd rather not risk it discoloring things long term.