Slight modification, another grandiose plan for a huge story. This one might just work, though.
The plan is this: The mad scientist works for the government. The government wants to take over a foreign country, and wants to find an insidious way of disabling its enemy's resistance. They plan some sort of propaganda campaign which will totally obliterate the enemy's will to fight. So the mad scientist, being a sexist mad scientist, proposes a plan: make all the men in the country effeminate, and they won't want to fight. It's a simple idea, but how does one accomplish this?
The scientist has done research into gender identity and behaviour. He hypothesizes that if men wear women's clothing, and are publicly exposed as transvestites; and if these men are well rewarded for their gender-bending, they will inevitably want to become girls. Thus, if he can effectuate his plan, the men will become girlish in no time. Implementation would be easy: Send in some female agents to seduce some of the men, and coerce them into femininity, and quickly the idea will spread. The details are unimportant. Suffice it to say that the government thinks the idea could use a generous grant for development. The scientist is commissioned to carry out whatever experiments he thinks will prove or disprove his hypothesis.
So the experiments begin. The story is a logbook of his experiments. He must try different methods of effeminating men: with force, with coercion, gradual, sudden, etc. And he must try with many different men, each of whom has a different sexual history. Thus, for each of the conditions, he must have a transvestite; a closet transvestite panty freak; someone who has maybe thought about it once or twice, maybe even tried it; someone who has never even imagined wearing women's clothes. And so I have a dozen case studies right off the bat.
Anyway, with all of these experiments, he gets to see the shocking results: he was correct. Men want to become women when exposed to their underwear, particularly suddenly. This alarms the scientist, and he takes drastic measures.
As a shock ending, his prisoners, who have been transformed from mostly virile men to chicks with dicks, revolt, and capture him. They plan to strip him down and force him to wear the sexiest lingerie imaginable, because they know that it would instantly transform him into a quivering mass of sheer girlishness. But when they take off his clothes, they discover, to their horror, that he is already wearing lingerie, under his men's clothes. He reveals that, as his experiments proved his hypothesis more and more, he became more and more frightened of what they might do to a man's psyche. He had watched hundreds, perhaps thousands, of men willfully forsake their masculinity, to a most disturbing degree. He saw men who never had any transsexual fantasies beg for bikinis and brassieres and garter belts to wear. He did not want to ever become subjected to such a horrible devolution. So he tried to immunize himself from the effects of women's clothing. Here we enter the hierarchy: here is a man who must at all costs keep a very tight watch on how far he goes and how fast. He started out with pantihose, and over his own underwear. He did not dare risk his manhood further. Then, when he felt comfortable enough in it, he dared to wear it naked at least ten times, until he could become used to it. And so on until he got to the point where he could wear lingerie. He wore women's underwear all the time, just to get used to it, in case he might ever be forced into becoming effeminate. And so he forsook his own underwear for women's wear, only realizing too late that he had somehow succumbed himself to what he feared would be forced upon him.
In the end, after this little brouhaha, the enemy forces attack. They are all effeminated men, and they force the entire population to become female like them. And they all lived happily ever after.
So what are all the possibilities for test victims?
1) raving trannie, out of the closet
2) closet girlie, highly experienced with women's undies, like me
3) only slightly experienced trannie, too scared to wear undies more often
4) someone who has only thought about it a couple of times
5) Someone to whom the idea of wearing women's clothing has never occurred.
And what are the possible test? We first have to figure out the variables:
1) amount of force (ranging from free choice to violence)
2) severity (start with lingerie or with nothing?)
Each man is forced to tell how far he has gone, with the help of truth serum. Imagine the embarrassment of number 2 and 3. I think you can pretty much rule out 1. The rest will be quite a blast.