You pay 10 euros for the week for each towel and when you hand them back you get 9 euro back. If you want to change them you pay more.
You pay a deposit on a towel and get most of it back when you leave
You don't have to bring towel from home. We were there 8 days, and I Only had hand luggage
Get an answer from Bull Dorado Beach & Spa staff and past guests.