I put it in reverse at idle when I start the turn into the slip. The prop walk helps to swing the stern around. Sometimes if there's a headwind I'll actually stop half way into the slip, but I like that as I can then use forward power and rudder to controllably position the boat in the slip.
Not how the books tell you to do it, but it works and the boat is always going very slowly so that minimises the time spent removing white marks from the blue awlgrip.
1984 Bristol 31.1
Alameda, California, USA