Is it forbidden for a Muslim woman to use brushes made from pig bristles in her work at a beauty salon, and does the prohibition differ if the client is non-Muslim?

It is impermissible to use a hairbrush made from pig bristles, and this is the view of the majority of scholars from the Hanafis, Hanbalis, and Shafi’is, because it is impure and there is no necessity for its use. The Malikis, however, are of the view that pig hair is pure if it is shorn and not plucked, while Shaykh al-Islam Ibn Taymiyyah held that all hair is pure, including pig hair. Nevertheless, it is more cautious for a Muslim to avoid what is disputed regarding its impermissibility, except in cases of necessity.