I don't know if you're a Cheech and Chong fan, but somehow you reminded me of the car made in Mexico entirely out of pressed marijuana leaves that they drive up to the border crossing control and then - - while they're in line waiting, next to a carload of nuns, some of the car starts to burn and the nuns breathe in the smoke unwittingly and get high. I think maybe it was Up in Smoke.
But sure, why not? Dirty bomb in bales of marijuana. Great idea. The jihadis better pray that the weed doesnt' catch fire next to a car full of nuns while they're waiting in line at Customs.