Yup, I'm not sure how prevalent it is any more, but you used to be able to buy suppressors ("silencers") for guns on Amazon, that were mostly advertised as "law

Yup, I'm not sure how prevalent it is any more, but you used to be able to buy suppressors ("silencers") for guns on Amazon, that were mostly advertised as "lawnmower mufflers" with very blatant wink-wink descriptions, like "this particular muffler works on 9mm exhausts, and will let you mow all morning long without overly disturbing your neighbors".