the problem with using this kind of 'logic' to cover up smuggling is that -nobody- plays along with it.
I've tried hauling a mix of synthetic marijuana, cardamine, and a large amount of pharmaceuticals to try and 'mix it all together' so the coppers cant find my smuggled goods, and they still go "HALT! YOU HAF TEH CONTERBANDZ!"
Hell, you could be carrying ONE unit of cardamine and they'd still try to shoot you for it.