Canister for vanishing a silk

We have no written instructions for this item and no knowledge of who manufactured or sold it. The likely routine is as follows. The performer shows a silk handkerchief before tucking it into the tube and placing the caps on the ends. Just before giving the canister to someone to hold, the performer removes one of the caps to show the spectator that the silk is really inside. The performer walks well away and says that the silk will vanish as soon as the spectator says the magic word. Sure enough, when the spectator opens the canister, the silk has vanished.