Shoot some bullets out of the weapon that you want to disguise. Then, reload while shooting. As soon as it reaches the active reload area, change to smoke and throw it. Then, switch to the gun to be disguised, then to the weapon you want to use to hide the weapon. Repeat the steps from the change weapon part. For example, you can use the shotgun and disguised it as a pistol. Your screen will display the weapon you wanted to disguise; other screens except for the host will display a pistol.