Their bodies are not for sale. The act is. The dance. Just like the act is for sale when you go to a theatre, a show, a rock concert, a comedian etc.
It is entertainment, maybe not entertainment you enjoy, but entertainment nonetheless.
As for your control theory, these men are customers, not employers. Are the customers in control of waiters and waitresses in restuarants? Barmaids in pubs? Till advisors in a clothing store? No.
The employer is the person who owns the establishment, and if his establishment is not fit to work in then it should be closed down, just like any other establishment, but if it is run well, with careful consideration for his staff then it should be allowed to continue to operate. (Please note; I said 'he' regarding the owner, this is not always the case, some establishments are, ofc, managed and owned by women).
Lastly, your employer does not control you, he offers you a trade, your work, for his cash. You choose whether or not you wish to accept that, therefore, you not he, are in control.