Okay, so it's natural.
Okay, maybe it can. That is not enough to convince me that hyperventilation is an effective treatment regiment or under what conditions it should be induced, and it doesn't really tell me much about PTSD.
Okay, maybe some doctors do use it as a technique. That does not tell me if it's an effective treatment regiment or under what conditions it should be induced, and it doesn't tell me much about PTSD.
Okay, maybe flashbacks can be resolved by allowing them to emerge. But this doesn't tell me if encouraging flashbacks is an effective technique, or under what conditions flashbacks should be encouraged.
You're repetitively using "can" language, but that's not good enough. I "can" get a lot of money in the stock market if I invest all of my funds in it, but that's not useful to me. I need to know what the risks are, the likelihood of payback, and the like.
In order to convince me that a treatment is effective, telling me how natural it is tells me nothing useful. Telling me what it can do tells me nothing useful. Telling me whether or not there exists people who use it tells me nothing useful. I believe treatments can only be called effective if they have an established likelihood to achieve a desired end without causing more harm. Whether they merely have the possibility to bring about a desired end is severely undershooting this dare I say very reasonable burden.
And this is less than useful to me. You're simply speculating on why people don't agree with you. This doesn't tell me anything at all about the validity of your views. Even if this speculation is entirely true--even if we develop an intolerance to the notion of hyperventilation treatment and encouraged flashback regiments because we're somehow culturally influenced by christianity--it could still be a bad thing. Whether or not it is true, therefore, has no use to me.
The motivations that people have behind forming an opinion for or against a treatment regiment tells me nothing about the effectiveness or lack thereof of the treatment. Again, what I need is something that convinces me that you have knowledge of its likelihood to effect a desired outcome without causing greater harm (and by knowledge, I do not mean certainty or belief, because I'm already convinced you have that, and that does me no good; I mean, instead, some sort of reason to think that the actual truth of your claim is the cause for your belief, as opposed to the banal psychological forces that people use to convince themselves of things that are not the case.)