I don't use a SS grip, but I do use an oversized one on my putter (www.winngrips.com/.../jumbo).
It's helped my putting quite a bit. Mainly it keeps my hands a bit more quiet than they used to be. I find I've stopped pushing a lot of putts right like I used to.
With any luck as mentioned by tdogg21 it'll help keep him on line on the weekends. Maybe it'll just have a placebo effect, but if thats all he needs, then they work for him ;)