I have a 2 blade folding on my 31 foot fin keel. It is over propped (although I now think it is overgeared). She walks to port in reverse. Waves tend to make the prop blades bounce a bit and cavitate (it needs a service), so she walks a bit over the place in forward when a bit of sea is running.
My technique, but others may have a better solution. In reverse I give it lots of revs to start moving, then back into neutral and try to steer back onto the required line, then enqage reverse again at idle. Sometimes I have to engage forward again to get the nose back online, then back into reverse.
Mine will reverse very well up wind, as the nose will tend to stay downwind of the stern at idle.
The folding prop on mine makes a huge difference in sailing performance. I just lock it into reverse once the engine is off and the prop folds away nicely.

oldlearner said..
I have a 3 blade fixed prop on shaft drive on a 30ft fin keel sloop. I have great difficulty with propwalk, always a tendency to steer starboard going ahead and in reverse its a nightmare the stern swings rapidly to the starboard rotating the bow to port, impossible to go dead astern.

I have found a 2 blade folding prop, that was possibly the original on this boat years ago but looks like it could readily be renovated with new bearing pins etc. I assume that it was replaced by one of the few previous owners who was into cruising and not racing.

What are the chances this will reduce prop walk, as well as improving my sailing speed.

G'day oldlearner,
have you tried leaving your rudder hard to port when reversing to offset the prop walk? And even more weirdly, leave it hard to port when going forward?
This is for manoeuvring into a dock, not toodling along obviously :)
like EC said, use lots of revs momentarily then back off to idle as the boat moves. Use forwards backwards, revs to generate movement, then idle.
i know it sounds nuts but if you have a centreline rudder give it a try. Uses flow over the rudder to counter prop walk.
Sucks big time if you have dual rudders :)