Solvent Traps are legal cleaning firearm accessories and are very useful for cleaning firearms. You cannot, however, modify, alter or redesign them into a device for silencing, muffling or diminishing the report of a firearm without first filing and receiving back from BATFE an approved Form 1. Be aware of the restrictions and regulations.
Solvent traps are a “firearm accessory” as such they can be attached to the end of the barrel, with an adapter, as a cleaning accessory and are not considered as anything other than an accessory because a projectile, or bullet, cannot pass through the tube without modification.
Solvent traps can be purchased legally without a Form 1.