Scenting is an effective way to fool/trick a snake into taking a food item they might not normally have in their diet or may not be used to eating.
I've had snakes that needed pinkies scented with worm for awhile until they acquired that new taste. After that scenting wasn't needed.
I've scented nightcrawler and pinkies with fish scent to get my ribbon to both items.

In my opinion the strongest scent is fish, with mouse parts/fluids/blood running a close second.
I've found the least scenting power to be with worms.
If I prepare a dish of fish and add worms, I am scenting the worms with fish not the other way around.


The way I see it there is a
"Scale of Scents"

#1. Fish
#2. Pinky(parts/fluids/blood)
#3. Worms


Please correct me if I'm wrong or add your views into this but I've always looked at scenting in this way.