Sealed cans should never be used on a rimfire weapon. I can't remember if the octane can be disassembled.
I'm waiting for my stamp on an AAC Eco-9. It is inexpensive at $450 MSRP but very effective and light. It is longer than some 9mm cans as it uses older baffles so an extra one was added to improve performance. They are no longer made but plenty are still out there. The class 3 dealer near me still has them.
I just asked the same question about .22 cans. My dealer has TC, Sparrow SS, SWR Spectre II and warlock II, and AAC Element and prodigy. I did not listen to any of them but got to hold them all. TC are sealed. The AAC cans were much more expensive than the rest. I wanted stainless for easier cleaning and durability. That left the Sparrow SS and the Spectre II. Both had the same 41db reduction. The Sparrow was more expensive by about $90 but is an inch shorter and lighter. The dealer gave me another $25 on the pistol I was trading in if I wanted the Sparrow so that sealed the deal. There was a very noticeable difference in size and weight with such small cans. Now my 7-8 month wait begins! I'm almost 7 months out since my check was cashed for the Eco-9.
Oh, Silencerco and SWR are the same company and they have fantastic customer support.
I can't answer your residency dilemma. The ATF is picky about crossing state lines with NFA items.