Q. Can I have my sheital washed and set in the 9 days?
A) Horav Shlomo Miller's Shlit'a and other Poiskim's opinion is that a woman's wig is considered a piece of clothing. As such it is subject to the restrictions of washing clothes during the nine days. (Piskey Teshuvos 551:20). They also prohibit professional combing and setting of the hairpiece. (ibid., Y'shuos Doniel p.45, Halichos Emes p.91).
Non-professional home combing is permitted.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit"a