As with any job interview, you need to prepare by thinking of what they are looking for in an employee for that job. Educating to increase sales, demonstrations, one on one advice giving, facilitating classes, etc. Why do you think being a man would be a negative? Then be prepared to address how you are going to overcome those issues. If you feel they would want a woman because women are more likely to speak a woman, then tell how you are able to build rapport with women, etc. If you have education/training in fetishes, be sure to include that on your resume. You can also offer to do a free class at the store. Make it a topic you are very familiar with and one that will bring people into the store. A free class is something smaller stores are open to especially if it is a topic that will bring in customers that would not ordinarily come in.

Another way to get an in is to build a rapport with some of the key staff. Tell them you are interested in a position like theirs and want to find out more about their job and working for the company. Ask if they worked at other similar companies? If key staff like someone they will often refer them and put in a good word. It also looks good to the manager if you are a customer who already knows about their products.