Vanilla is one of those old-school myths you still hear now and then.
I'm not a huge fan of Bob's videos. He seems like a nice guy; he's funny; but he hasn't kept snakes for all that long. He's entertaining but I wouldn't take husbandry advice from him.
Reptilinks sells ASF juice for scenting as well as frog juice for scenting for reptiles that eat amphibians, and some other scenting juices. I'm still not sure what the fascination is with ASF as feeders for Royal pythons - ASF aren't really a common native rodent in their habitat. But the various scenting juices can be helpful for specific reptiles. I'm not at all convinced of their utility for Royal pythons, as feeding refusal with Royals is husbandry-related most of the time, and not related to improper diet or the need to tempt them with other scents.