I've actually been working on this shot for the past couple months, and every now and again I can pull it off. First suggestion: Don't use the 50* wedge. Use the 56*, maybe even the 60*. I have found that I can make the 58* take one bounce and stop, while the 54* takes a bounce or two and then releases a couple feet. Second suggestion: try to keep your arms and wrists as relaxed as possible through the swing. The more I tried to force the club and "nip" the ball, the less spin I would get. Instead of swinging hard at impact, think about swinging smoothly (almost too slowly) back and through and accelerating right before impact. By taking a more relaxed swing and holding the finish low, I am able to generate a pretty good amount of spin. The feeling that I have is that I hinge my wrists almost immediately at takeaway, and I barely take the club back (for about a 20-25 yard shot). I then take a relaxed downswing and only think about accelerating (but not forcing the club) through impact. If I catch the ball properly, the flight is very low, the ball takes a hop and then either stops completely or rolls out a few inches. I'm still working on refining the shot, but I've found that it's a great way to significantly reduce roll without using a flop shot. It's a much more controlled shot than a flop, IMO. Good luck.