Not Legal Advice:
Yes, a dog's nose works differently than a human's nose works; while a human's nose tends to smell a scent as a whole, dogs can smell the individual components that make up the smell.
There are an impressive 5,000,000 cells devoted to the sense of smell in the human nose, however a dog's nose can have as many as 220,000,000! All these cells help the dog smell individual ingredients in what we as human's would likely consider a single scent.
We found one statistic that says a dog can detect a single tablespoon of sugar mixed into enough water to fill 2 Olympic sized swimming pools.
So the bottom line is that it's extremely difficult to mask, or hide, one scent by using another, or attempting to keep it in an enclosed space, when it comes to a dog's nose.
Recently the accuracy of drug sniffing dogs came into question at the Supreme Court; a suspect was pulled over in his vehicle and a drug sniffing dog indicated that there might be drugs present. A subsequent search revealed chemicals for making methamphetamine.
Two months later the same driver was pulled over by the same officer, and the same dog sniffed and indicted the presence of drugs; none were found this time.