The choking should be done before the case becomes entirely dry. As a preliminary to the process, a cord of size proportioned to that of the firework is attached by one end to a staple driven into a post, or into the wall, while the other end is fastened to the artificer's belt, or to a stick over which he straddles, placing it behind him across the buttocks in such a manner that by leaning against it the cord is tightened, and he is thus enabled to use the weight of his body in the choking. With the cord tautly stretched, the throat of the case is placed against it, and the worker, with that part of the string between him and the case, makes two loops around the throat, about one-half an exterior diameter from the extremity of the case. While holding the case with his left hand, a small stick of proportionate size is thrust within the throat by the right hand, to preserve the opening. The cord is then tightened as the artificer throws his weight backward. At the same time, he revolves the case, in order to distribute the choking evenly about the throat, until there remains only a small hole, barely sufficient in size to permit the entrance of the piercer.
It is necessary to soap the string to prevent the case, which is still moist, from adhering and tearing.
After a number of cases have been choked, they should be tied, lest the choking loosen. This is effected by passing around the choke three nooses of thread and tightening each loop in a knot, called the knot of the artificer. (PL II, fig. 21.)