How can a woman attract a gay guy If I need his attention even if I know a relationship will not develop can pheromones for women to attract men work on a gay do I have to wear the male one?

Well, if a man is gay he is by definition not attracted to women. No pheromone will change this, because you have a vagina. Therefore, you cannot attract a gay man in a sexual way at all, ever, under any circumstances.

However, if you need the attention of a gay man for nonromantic reasons, e.g. to make someone else jealous, etc., why not just ask him to help out with the situation?

You can't attract the gay man, stop trying. How would you feel if a lesbian kept trying to get you interested in her?