I personally do not use scents (although I keep a bottle of Smelly Jelly liquid in my tackle bag).
...I have seen others slather tubes in Smelly Jelly paste and get fast results using the "Erie drag." Was it from the scent? I don't know for sure, but if it's something an angler puts confidence in, I doubt that the use of scents would hurt the fishing.
I use bang crawfish alot on my tubes, jigs, and brush hogs. I also use smelly jelly sometimes. I have out days where I have had days where I have outfished others 10-1 using bang. It comes off easily in the water, but on ALOT of occurances I have caught a fish the cast after I sprayed it on.