A short time ago I had written on how to do some minor repair work on cargo containers. I had mentioned the odors that can permeate the interior of some shipping containers to the point that it would be a crime to store anything inside. Imagine clothing stored and then smelling of whatever horrendous thing was inside previously! Although we try very hard to purchase cargo containers that are free of odors, sometimes they magically appear after previous owners tried (unsuccessfully) to get rid of the smell. We have a full-proof way of fumigating our shipping containers that takes elbow grease, but does work.
You’ll need a pressure washer for this job. With a straight mixture of bleach, pressure wash the interior of your shipping container for a good 30 minutes. Pressure wash the floor until a small amount is stripped. Once that’s done, sprinkle a 3 lb can of coffee on the floor, shut the doors, and leave it alone all night. The next day sweep it out, and that will leave the cargo container smelling, well, of nothing at all except for maybe a hint of coffee. You won’t even smell the bleach that was used.
There’s nothing more noxious than a smell that’s unrecognizable and just awful. Shipping containers can stay smelling clean if you follow the above steps.