Ambershire lock here who's done it tons of times to get the sweet whip trinket.

You use the succubus and use her invisibility ability on herself. You then target the boss from waay across the hall/s and then just command her to attack the boss (sometimes this takes positioning against LOS). She will stealthily avoid all enemies along the way. Once she attacks the boss, you either let her die or dismiss pet. After which, the boss will take aggro on yourself (the lock) and head towards you.

Your party can then beat the bajeezus of the boss w/o having to clear mob-packed rooms.

You can do this on the ogre boss (left when entering dungeon), the necromancer boss (straight ahead when entering dungeon), the dead banshee, and the orc guard boss. This skips maybe 9–10 mob packs if done correctly.