Ive never seen anyone with one locally.
Heck you may even be able to bring that in from the UK. Its debatable I guess. Its mentioned that the CBSA doesnt seize silencers if they do not actually silence and only replicate the look. Im not sure of the details.
Heck if I was the CBSA agent inspecting the box and opened it, I would be like
"what the hell is this thing?"