Not familiar with this product but it sounds very similar to Waxoil or Eastwood's Rust Encapsulator. Both are a waxy type of protectant. Each claims to be better than the other.
I prefer these types of treatments as they do not dry out and trap water and, just as important, are easily removable. That said, if you search the forums you will find lots of experience with all sorts of miracle treatments ranging from Por-15 to foam and Gluvit (all bad). The general consensus is that rust protection starts with proper treatment of the base metal. If there is ANY oil or residue, these products will often do more harm than good.
The absolute best approach would be to completely strip the metal (chemical or blasting) and then have it hot dip galvanized. Unfortunately, this is costly and there are very few places that can do this work. Second best is to again get down to absolutely clean metal and then use an epoxy primer prior to paint. Just remember that the good two part epoxy primers are very bad for your health and you need to have a respirator that pulls in external air. Once that is all done, then stuff like the wax based treatments is good added protection in areas like inner doors and quarters.