Speaking from a human perspective, cocaine has a smell that is unique that smells like, well, cocaine. I can smell the HCl or the citrate and they both smell like cocaine, and I have had citrate in my possession many times in the past, so I know it still smells like coke. So do you really think a dog wont be able to tell? I'm just asking, honestly, not being a smart ass or anything. If its true that the dog is smelling for a very specific nuance that we can't even detect, that would be great news.

Pure cocaine has no smell.

I once lived next door to a ”retired” drug sniffing dog, whilst actively participating in some less-than-scrupulous behavior. Everytime I met the dog, he would just sniff at me, but never get aggressive, indicating (to me) that the dog required some sort of indication from a handler that he should be doing his job (?). Also, I maintained the guise that I wasn't fond of dogs to limit interaction...
Just meandering...