Folks:
Even if a small amt of odor remains, it's a few parts per BILLION. Not to worry.
Using a sponge/rag and a small amt of sanitizer is better: it is cheaper; you will be more likely to finish the job. Why, you ask, is this important?
PET, polyethyleneterephthalate, BBs, is a polyester. Esters can be hydrolyzed(cleaved by water), and the reaction is accelerated by: acid OR base, time, and ESPECIALLY elevated temperature. You could dissolve some of the inner surface of the 'boy.
Just for S&Gs, get a piece of nylon, not an ester, but an amide, close enuf for our purposes, and soak it in warm acid or lye.
PS: It is unfortunate that the same word: polyethylene, appears in both PET and plain old polyethylene. It is misleading. Old poly is highly resistant to chemicals. PET, well, just be careful.