Quoted:
Take your time and read it. You have to register each oil can. Thats expensive. Sure you can replace the oil can, and get away with it. It sort of implies you can just buy oil can replacements. But they sell you a oil can with a serial number. Hell you can buy the adapter as away to clean your barrel for capturing oil from your barrel (Bunch of BS if I ever did hear). It's a real bad idea if you really read the site. I wont chance my gun rights on any thing like that.
I remember the soda bottle adapter that was made to catch the oil/rinse from your barrel about 20 years ago, it was used as a silencer too
and soon after ATF caught on and made a new rule against it.
I'm thinking the adapters that should be used as a oil catch will get used for
for the wrong thing and soon I would think they will get banned just like the soda bottle adapters..