Its used in USA for agriculturists to keep the fertilizer from plugging up the irrigation works.

I first saw it for home use in Japan - it does work, but the Japanese magnets were a lot stronger than the US ones.

Here in UK they use electromagnetic for the same effect. 10 wraps of the pipe with insulated wire going to a power source. It would most like likely be a low poer DC source-but all the manufactures have their 'Black Boxes'- haven't had a chance to use a multimeter on one yet to actually tell.