I think that the ultimate goal of performance is all about 3 things, being very slippery for minimal drag as one moves the wrist up and down and, if lucky, have a material that wicks perspiration and finally is affordable and relatively easily available.
My personal choice was to use a nice padded leather strap, it seems that it slides easier for me than velvet or other materials, but I wanted to gain more. I did that by looking at what some others were using and then making my own for a few dollars.
One of the slipperiest materials I ever had the chance to wear were sports rash guards. Mine cost me $10 and from that I was able to make several from one t-shirt. The material is a bit like spandex but more importantly it wicks perspiration and slips incredibly well… so well that the first few times that I was using it to practice large bass jumps and instead of missing the jump, overshot it by 3 rows.
Via the kindness of my mother and her sewing machine where each set took about 20 minutes each to cut and sew, we made 2 grey and 2 black ones later on from that one rash guard. I gave the grey ones to my uncle who uses them and I kept the black ones. You can check them out
HERE.
Of note, I specifically made them way longer to accommodate the fact that when playing my Morino free bass, it is so huge that my forearm rests where other accordionists have their wrists, most will not need that extra length and therefore even easier to make.