Does anybody use these?  Do they really help?

I'm having some knee/leg pain, and I'm not sure if it is related to my slide or something else.  I used to have a pair of Dexter Alan's, but bought a pair of Lind's PSS with 3 different soles, and haven't really had any pain since I've been using them (occassionally some slight pain, but nothing like before).  But recently I started having pain in my knee and outer thigh.  It usually went away after bowling, but this week it has stayed with me all week - although I did spend much more time commuting and sitting in training class, so that may be adding to the condition.

I don't know if I just need to clean the soles - I take a scotch brite to it every few weeks, or if I need new shoes.  I was wondering if those slide socks really work - would be a lot cheaper than buying new shoes (again!).


http://www.buddiesproshop.com/product/679/Ebonite+Shoe+Slider.htm

http://www.buddiesproshop.com/product/700/AMF+300+Shoe+Slide.htm

I bought an ebonite slider from the pro shop yesterday.

Tried it once and almost wiped out!  Had trouble with my approach - couldn't push off with my left foot, and almost messed up my leg (started sliding backwards!).  

Will have to try it again another time, but I don't think I will get much use out of it.