I was wondering some things about Quelling Strikes, on how it works exactly, since based on this there are optimals way to use it for maximum enmity reduction.

What I was wondering is, how exactly does quelling lower your enmity? Does it:
Lower your enmity on each attack
1) based on a % of your current enmity?
2) based on a % of the damage of the attack
3) with a static amount? if this -> does the static amount scale?

Also how does it work with auto attacks? And with DoT's (initial damage and DoT ticks).

Any input on this is greatly appreciated!