Pelz gets a lot of flak for his teachings and it appears that less and less Tour players are following his advice these days. But, that doesn't mean he doesn't have some good training aids. I currently use his putter clips (pic below)
These are designed as a feedback device so the golfer knows when his putts were not almost perfectly struck in the sweetspot. If you look at SAM puttlab results for most pros, they are extremely consistent with where they strike their putts and usually it's on the sweetspot (unless you're Meg Mallon who consistently strikes putt more towards the toe). Amateurs on the other hand tend to have a bigger dispersion of where they strike the ball on the putterface.
I used these putter clips frequently just as a reminder for me to not use the right hand on the thrustroke. I believe on letting gravity do as much of the work as it possibly can on the thrustroke. When I do that, it does a lot of good things for me...in particular it allows me to consistently strike the sweetspot. When I start using too much right hand, that's when there starts to be some dispersion. The putter clips come in a set of three and the adhesive is superb. In fact, I wish the LPAS training aid had Pelz's adhesive tape. I've had the same adhesive for more than 3 years and have yet to change it over or have a problem with it. You can buy the putter clips for $29.95.
The other training aid Pelz has that I really like is his 'Truthboard' (pic above). I actually don't have this, but a friend of mine does and I've used it a bunch of times. Obviously, it looks like a rail that is on an incline that is for 3 foot putts. But you can adjust the hole size and make the hole smaller and adjust the level of the incline so you can give yourself left to right or right to left putts. This is a GREAT tool for getting your launch (the initial 2-3 feet of the ball leaving the putterface) down and help with those knee knockers.