I remember when I made a knife back at the end of winter and used some dead Ivy for a handle, there was a question as to whether Ivy being of a 'layered' construction would be suitable. I wondered myself, but was attracted to the natural form of the wood and decided it was worth a try.
After a summer of hard use (no Battoning) I'm pleased to report the handle is completely unaffected by frequent use. Early on I did sandpaper the handle profile slightly, and now it is supremely comfortable to use.
PS. Didn't really make the knife, I just made the bolster, pommel and handle. I bought the blade......