I use lure at pocket sets for rats. I am not sure how much extra draw the lure has over the hole in the bank at the water line, but I figure that hole fills up with the scent and then the air currents over cool water keep the scent right about a rat's nose height as they swim by. I make a lot of rat pockets with grassy overhangs so that they are not readily visible to other individuals passing by, so maybe they don't have as much eye-appeal to rats either. I've used several different lures and brands with varying success. I like gland lure, especially in spring but it works in fall also. I've also tried lure with noticeable mint added, and I used one that smelled a lot like cherry cough syrup once and it worked OK for me. I think the more natural scents like gland lure, or maybe a food-type like carrot oil, or fennel seed oil, seemed to work better for me. Might not be case in all areas though, but that is what worked for me anyway.
Good luck!