Anaesthetize (verb) means “apply a chemical in the dry cleaning process that smooths fibres and makes clothes dirt and stain resistant.”
The chemicals that different dry cleaners use when they anaesthetize clothes vary, but they all have the effect of relaxing the fibres in materials and, as a result, making the fibres lie flat. This, in turn, means that dirt and stains are less likely to get trapped between erect fibres.
Because the chemicals quickly leach out onto the garment-wearer’s body, the anaesthetizing process must be repeated with every cleaning.
When dry cleaners anaesthetize clothes, the chemicals they use are, by law, all certified to be only mildly toxic. You would have to wear an anaesthetized shirt directly against your body (i.e., without an undergarment) for at least three hours straight before it would become likely that you would encounter any ill effects, such as a rash, abrasions, bruising, cardiac arrest or cancer. Furthermore, you would have to wear anaesthetized shirts for four hours a day, four days in a row before the probability of the toxins having a fatal effect would reach even 10 percent—25 percent, tops. (If you also wear an anaesthetized pant or skirt in addition to an anaesthetized shirt or blouse, the time to possible fatality or other harm decreases somewhat.)