I'd call up your trash disposal company and see if they are in error.
All of our color machines use waste bottles that Xerox doesn't want back, so we dump them without issues. I don't know how the 5000's "diaper" comes to you, but on our machines its a clear plastic bottle with a cap, and we put the used bottle into the ziplock bag that the replacement came in, then put it in our normal trash bags, and out in the dumpster...never had any issues.
If your garbage company doesn't want them then I'd save them for your techs and sales reps and "regift" them...
If you are just throwing the bottles in the dumpster directly though I can see where maybe the garbage guys wouldn't want them like that.