Re: CO poisoning: you might also consider a short, large diameter breathing tube that you could wear during this exercise. Something like a snorkeling tube with an extension. Breathe in through your mouth, and out through your nose. And do this outside - not in a garage.
Also, My SIL grew up in Texas. She says that the roaches dine on the glue holding cardboard boxes together. That’s why they transfer everything to sealable, plastic bins when they get home from the store.