I would also wager that at least 0.01% of ALL WGs listed on Adultwork, etc claim some form of benefit.
That doesn't hold up to logical thought though.
Many of these girls doing this are in their 20s. They are doing it secretly without their family's or partners knowing. If they want to keep the secret up they need to do what normal unemployed girls do and that is claim benefits and pretend to seek normal work.
If their families ask, where have you got the money to pay for your house, rent, water, electricity and all your bling lifestyle when out of work and you do not claim any job seekers allowance. What will they possibly say in response? The need to claim benefits to have an excuse of where the money is coming from.
I would say a better number would be ~90% claim benefits.