The only strippers I've ever found that worked
well on wire wrap were those ones that looked like
small pliers and had white plastic shells that would
guide the wire onto stripper blades. I'm not sure who
The newish Cut-and-strip tools work pretty well for me
(
http://www.okindustries.com/products/4.1.1.12.htm)
The problems I have (with any tool) are holding the wire, and constantly
switching tools between the stripper, needlenose and the wrapper.