Create your own trial.

[Kosmos992k]

A trial where upon entry, if the game registers that you're wearing accessories that don't correspond with your primary stat(s), the boss vaporizes you then permanently deletes your SE account.

Nah, make it so that the disrespect (toward the boss) shown by a player facing a boss with such inappropriate gear enrages the boss immediately and especially against that player. For the duration of the fight the player will generate several times the amount of hate than normal for the duration of the fight.

and...

Unless they're a tank, then it degenerates hate.

which is an awesome suggestion that I agree with wholeheartedly.

Additionally, Queuing with inappropriate gear could be seen as griefing since it immediately creates far greater potential for a wipe.

Then we might see how long it takes for peer pressure to make people use appropriate gear.