You may also ask the hotel receptionists, and taxi drivers for help. They may introduce you to non professional local or tourist girls. There are girls around that seek a vacation boyfriend, and many girls love foreigners. Nice, with swimming pool. About 10 girls that came from other towns and live there 24 hours a day, to make money for a month or two.
Place is open in the afternoon, closes for a few hours, and reopens at night.
The girls are wholesome next door girls, not the typical whorehouse trash. I met one making money to study for the college entrance exam. Porto Seguro is about 19 hours by Bus from Rio. You can try to get package deals from travel agencies like Soletur. There is a youth hostel, some cheap boarding houses, you may try to get an apartment for rent.