I split out 17 staves in the late summer, the bark didn't slip and it took me two weeks to get it off all my staves.
I had some beautiful straight staves and some that dog legged to the side after they dried and so far have been impossible to straighten with heat or steam after several attempts.
A friend who only makes hickory bows and lots of them, he splits his logs in half and leaves them that way for at least 6 months before he splits the halves into staves. He says he gets very little warpage that way.