It is allowed for both males and females to clean the chest and back hair. However, it is not lawful to make eyebrows. Yes, if some excess hair grow around the eyebrows which make it ugly then it is allowable to remove that extra hair. (Ahsanul Fatwa, vol. 8, p. 76, pub. Darul Isha’at, Karachi).
Allah knows Best!
Darul Uloom Deoband