Yea, if it dont smell like weed, and does resemble the odor of a chemical instead, its probably been messed with...

But, SOME Mexi brick weed (schwagg), that Ive had, has been brought into the U.S. in gas tanks and other canisters that contain chemicals, to deter K9 detection, when crossing the border, so sometimes the smell is just from the shit being packed in and around chemicals that make it smell messed up...Smells can be deceiving. Doesnt always mean that its been messed with. The times Ive had stuff that you could tell was messed with, you could just tell.