those "smelly proof" bags are RIPP OFF, plain and simple.
Why? This is chemically explanable.
NO containers can make the molecules stay inside. The molecules WILL permeate whatever you use!
Sniffer dogs can smell weed compressed INSIDE a sealed acrylic tube, placed INSIDE a car gas tank! How? Because the molecules WILL PERMEATE.
It's just a matter of time. 1 hour? 12 hours? 3 days? Depends on the container.
Try it at home! Buy one of those bags, put a tuna fish inside, and lock it.
You CAN'T smell the fish when you put your nose on the bag.
Now come back like x hours later, put your nose on the bag again. You WILL smell the tuna fish.
A regular ziplock bag will do the same effect if used for a several days travel! Don't spend your money on that, this is an illusion!
Peace
