Yes.

Having recently spent a couple of weeks camping, I stropped on my jeans before shaving and it was fine. You could try taking an old pair of jeans and making a denim strop. I use a denim strop regularly and it works fine although I'd have concerns about whether it would have trouble staying flat after being repeatedly rolled up (I suppose it wouldn't be hard to iron it flat or hold it under a hairdrier when it gets crinkly).

In all honesty though, when I see a Harley it usually has so much leather paraphernalia stuck to it or worn by the rider, that there must be endless leather surfaces to strop on.