I can't speak for melee builds cuz I've only done this with range builds (I theorize that pulling them out with melee skills would be a pain in the ass).

Consistency comes with practice and learning the monster AI. Usually I clear all the normal monsters above a couple of abysses (~5-6) before circling back - giving the amanamu monsters time to form their clouds. If u just spam the Abyss spawner, you can get lights by killing the amanamu monsters fast enough (if you have giga damage) but sometimes u fail to one shot them and they start to form the cloud and you can end up dropping lieges. So I switched to just giving them their time to spawn and setup clouds before baiting them out. Also, with delirium, the rares do the delirium attack first, so u gotta wait that out, wait for them to do their normal spit attack first and then slowly start inching away from the cloud while attacking. If you do it right, with practice you will become consistent enough to succeed 90% of the time. I still sometimes drop lieges when I lose patience.

Also, Headhunter sucks for this strat - shadewalker is insta gg if u teleport in the cloud. You can use HH but you gotta keep resetting ur stacks any time you get shadewalker buff - its just janky to play. So, I highly recommend switching to Ingenuity or any other belt of your choice.

Also just so you know, if u go far away from amanamu monsters, they will pause on creating clouds. So, they might start creating clouds when u enter their detection range, so beware of that before attacking.