So what approach would you suggest? Those camps and therapists always suggest paying attention to the opposite sex, as you suggest. They suggest not paying attention to the same sex. They try to get people to really think and be attracted to the opposite sex. They seem to do exactly what you are doing. And to top it off, often the people at those camps and therapies sincerely want to change. I can't imagine a better test of whether it is a choice or not.
Regardless, they do serve as evidence that attraction is not a choice. So your claim "there is no evidence" is false. Where is your evidence that attraction is a choice?
I don't suggest an approach. I hold lightly to my belief that there shouldn't be "an approach." I dispute your claim that my claim is false. I uphold that failed trials do not prove the opposite hypothesis. If it were another topic, I think you may agree with that notion.
My evidence that attraction is a choice is as weak as yours is that it isn't. Bisexuals exist. I have heard 1 gay woman, (the president of the local GLYS), in answer to a question, say "I'm gay because I don't do sex with men." Certainly, a man could get her off. Whether she is attracted to the man or not is a choice and that choice is influenced by many factors:
1) Is there such a thing as homosexuality?
2) is homosexuality detrimental to my well-being? (ppl choose to do many other things that Are detrimental)
3) is there opportunity for me to try homosexuality?
4) am i willing to try? weigh the pros and cons
5) Am I truly doing this for me?
6) am i willing to be honest in my attempt despite perceived, possible social consequences? -a key point that may have caused those failed, misguided therapies.
7) after trying it, do i like and can i sustain the results?
-Not a comprehensive list.
A failed attempt by one or 1000 individuals only
suggests that all others will also fail.