I am a big fan of using bicarbonate of Soda/Sodium Bicarbonate - put your towels in a bath of it in solutions. It is great for absorbing smells in general - in shoes, fridges, funky smelling water bottles! I between summers at summer camp, when my water bottle was stored in friends Shed so I didn't have to cart it home, I would just put some in my bottle to prevent smells. Good luck