Okay, it's been a long time since I've contributed with something, so I thought I'd share what I just found out. I do not know if this has been posted before - if so, I'm sorry.
The trick is to get the "zombie debuff (disease)" and get on a flight path.
You should time it so that while on the flightpath you turn into a zombie.
Upon arrival at the town, start killing the low-level mobs. Kill 4-5 of them, now if higher elites attack you, you just use the "aoe disease" effect on them, and the 4-5 other zombies will help hitting down the timer. Within short time you can turn towns into zombie-towns.
Hope it's not a repost :wave: