My driveway is steep and I have to backup uphill while dodging two vans. LOL, I've only been driving stick for a few days, but it seems like the best way is to kinda slip the clutch like you were saying. When I back up, I just don't wanna let the clutch all the way out, but I have sometimes and yes, it is a fast and scary thing. I still have yet to perfect it, I'll let you know when I do