I use the dry scrape method,first it the hide is fresh I scrap all the meat/fat and membrane off the flesh side,very important to get the membrane off,all of it. Then
punch holes of the edge all the way around 3 or 4 inches a part. Then rack it up.
Loose to start and go back over a few times until it tight,being careful not to pull out the holes. Let it dry and it will get tight as a drum.Then scrap the hair off. I have a tool to do that but I have seen it done with flakes and have made some home made scrapers to do it with also. Slipping the hair may be a little easier but a bigger mess, I was taught the dry method and have never tried the wet.
Pappy