"Cocaine hydrochloride hydrolyzes in moist air to give methyl benzoate; drug-sniffing dogs are thus trained to detect the smell of methyl benzoate."  -wiki-

[EDIT] What if cocaine citrate (other salts) were used?

Sigma and ALL the other companies sell a methyl benzoate /cellulose/silica mixture in their 'drug scent' kits.

Post Here about any other information regarding scents, and substitutes...

From this data one should be readily able to derive, how to not get caught by a drug dog.

It likely detects a variety of compounds released from the cocaine, including the cocaine itself - I bet enough of it sublimates for the dog to detect it.

This is an interesting thread, there is another semi-related one that discusses perhaps deadening the olfactory neurons of dogs to prevent them from any detection, but nothing really useful was found in that thread.
See here: http://127.0.0.1/talk/index.php/topic,808.msg9660.html#msg9660

I too was thinking of the methyl benzoate thing for avoiding, and confusing dogs at festivals, it would obviously be a bad idea to use where you dont want to alert the hounds. . These dogs are obviously trained to detect these chemicals in a few PPM. I was thinking rather aim for sensory overload rather than anosmia as in the link vesp posted.
Highschool style synthesis:
http://rasayan.net/Documents/Chem123_Expt02_Proc.pdf

Yeah and Ive also read somewhere that dogs cant tell the difference between Hops and Cannabis so that might be a very cost effective route to investigate.
I dunno I suppose the lotion thing would work, I was more thinking of a water pistol. spray other people. other vehicles. even if it sublimates quickly, these dogs are trained to detect a few PPM. overload the dogs senses and the pigs workload!

dogs are always pulling people visiting in jail who have drugs in their system rather than on their person.
it doesnt seem to be heroin addicts but rather cocaine/amphetamine/cannabis users.
the cannabis is understandable, (smoke clinging to clothes etc)
do the first two have similar degradation products once broken down in the body coming out in sweat?
an idle thought been perhaps it is degradation products what are more "smelly"

Somewhere over the rainbow it was found that door handles (especially bathrooms), faucet knobs, pay telephones, and armrests/siderails on benches and chairs were frequently touched places. Think of all the places you don't want to touch during flu season. That is where the combination of the scent agent and appropriate low vapor pressure solvent belong.

At a festival, the handles to the portable toilets are by far the most handled surface.

Masking does not work against dogs and deadening is not reliable. If there are targeted scents the dog will detect them. The only way to defeat the dog is to make the dog's scent worthless as a discriminator between those possessing contraband and those who are clean. Think in terms of a denial of service.

The willingness of dogs to alert on trace, residual odors is far overstated. Law enforcement frequently lies to cover up true false positives as well as a handler's illegal signal to alert. Dogs can sense these trace amounts, but they aren't high enough to elicit an alert. Anyone who has ever watched a detection dog at work can pick up on this behavior on closer inspection. The dog only alerts when the odor becomes strong enough to meet the dog's confidence threshold. A properly trained dog will become frisky and inquisitive upon sensing a trace odor, at which point it goes to work trying to find the source. If it can't find a strong source odor then the dog sort of goes in circles before either giving up or chasing a false trail elsewhere.

If the dog alerted on any trace, it would do so upon entering a room with dope, rather than actually tracking down which pocket among hundreds of people the dope is in.

The detection behavior derives from the dog's natural hunting instincts. By its nature, the dog becomes engaged and active when it senses its prey nearby, but it does not become aggressive until it has found the target.

Forget about the wiper man, there are other tricks, assuming the local cell even understands the concept of a DoS attack. Lots of tricks, best not discussed.

They could also be alerting on traces of unreacted precursors in the final MDMA.

A valid point,
(come on, which of the industrial mdma chemists didn't clean their product?)    -All of them.

Good point. I have heard in mexico they pay people to wash windshields with drug laced water to mess up the border control.

I doubt Hops would work; beer doesn't set them off.

harass a skunk, then collect the thiols
 

How does that relate?

Overpowering a dog's sense might work.... but I'm not going near any skunk.

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.