Does anyone have any experience with using rayskin for Western style grips? All of the rayskin that I have inspected seemed to have a very stiff texture. Can it be molded the way rawhide can be shaped?

A lot of replica swords come with rayskin grips. I have a Scottish Basket Hilted Broadsword (Hanwei) that has a rayskin grip, so I know it can be used. But I don't know how it's molded.

Perhaps you can wet-form it like leather?

I haven't used rayskin myself, but there is a 3 part series on making japanese sword handles on youtube that mentions it. Here's the series (the second one is really useless specifics-wise, but it mentions soaking the skin in plain water. The third video is a little more informative):

http://www.youtube.com/watch?v=N16i--xj_mg&feature=related

http://www.youtube.com/watch?v=GyvzmSKVR9Y&feature=related

http://www.youtube.com/watch?v=YI0DHtqFKQ4&feature=related

Yes rayskin does become nice and pliable when soaked. I have used it on a couple of japanese swords and 1 1822 British Infantry sword hilt. Simple soak in warn water for 5 minutes, pat dry and wrap around the hilt. Trim up the butt joint. Use a wrapping of string to hold it while it dries. Getting the butt joint right can be tricky but you can peel off the skin re-soak and apply to make further adjustments. When I feel eveything is right I apply a thin smear of wood glut to the hilt before finally applying the damp skin and securing with string again to dry.