Yes. There are many misconceptions when it comes to the naughty industry of Thailand. The first itself is right from the local people. They believe that westerners are very rich. Yes, if you are crossing the seas for some fun, you need to have the green notes as well. It is advised to have cash in hand at your disposal. Most of the best soapy massage parlors in Bangkok will not accept credit cards. Make use of cash to any other local platforms for transactions.