I bought some of those @SugarJ and gave them a go.
It was a mind-numbing hour, and I think I found a whole other cat living in my keyboardbut I have to say it was worth it! I am actually a little surprised at how noticeable the difference is. I like the slight rubbery bump at the bottom, and it makes the keys feel heavier in a way. Deadens the sound a bit too, I think more of a "thwonk" as they say, although I never minded the sound.
Anyway, thanks! I am pleased!
Glad it worked out for you. I used those on the first board I had with red switches before I switched to browns.