does it work???

I bought these beer line cleaning units from a company called Innserve. I've gone to 1 line clean a month. They've posted something about it on youtube (right at the end of the video) People keep saying to me " ah magnets don't work" Although these things send out some sort of strong signal and have no magnets. I would like to hear from anyone that has had magnets in the past but now has this system now. ( works for me)
http://www.youtube.com/watch?v=lWaxKZdMFuI

Personally I haven't used them, but I can't say I ever would. Put simply, beer lines build up yeast and dirt that has come out of the beer. Any machine that doesn't allow this to build up is letting it come out into the beer. Or build up in the beer engine. On the ales I line clean at the end of the barrel on the guests, or for the regular ones once a week - any beer (flushed through with water) goes to the kitchen for S&A pie mix.