Electronic rust control module. Science or Scam?

I put one on the last new truck I bought because the frame on all my others scaled of rust what ever that new chemical is they put on the PA & ohio,pike..will tear the frame on a big truck up in three years.and I don't care what you do to it!!but didn't get to keep it long enough to find out,but I do know it was 3 1/2 yrs. old and still shind like the top!!!!if that's a help....Artie