Each to their own, but 3 in 1 is a lot cheaper. It is applied along the edges of all the beading, not just that between running boards and body. Stops squeaks and keeps rot at bay. Just gently run the can along the beads adjacent to the bodywork and leave it to soak in. Note, by next morning, you will find little pools of it below the wings where it runs off so if you have a carpeted garage or nice driveway, you may need to put some protection down first.
