I’ve had some luck with attaching silicone pie mat to prints that I wanted to have a grippy surface.

Downside is it picks up any grime, dust, dirt easily. No biggie when you throw a silicone mat in the dishwasher, more of an issue when you can’t do the same with something 3d printed.

Another consideration could be large furniture non slip pads. Something made for putting on the feet of a couch/sofa for example, cut to size?