Benedryl works very well for hot spots...it stops the itching which makes the dog scratch less so the spot can heal.
Zero my Central Asian got them when it was humid but now I know why and how he gets them so if we are going swimming on a humid day I give him some benedryl (1mg per pound of dog)
Hot spots can also be caused by an allergen in the air, detergents, something you spray in the air or something your dog is lying on as well as diet
Also...keep the area clean and dry and then use the regular listerine ( golden color one) and you can spray it on there...that will clear it up...gold bond poweder does the same...too
Good Luck