There are numerous examples where the conversion therapy has worked.

Inclinations are there for all of us but behavior is a matter of choice.  All of us have been angry enough at someone else to harm them back for the what they did, but we can choose not to take our own revenge.   When I see the deserts in the bakery display case in the grocery store,  I will want to try them, even though, as a diabetic, I know they are not good for me.  An alcoholic or drug addict can learn control their wants.  All of these examples are cases where a person can decide he or she wants to not give in to desires.  Would you deny them their freedom of choice?