Yeah, I farm the chests in Slabs between arena Qs.  HARP works well.  I'd fraps it, but I'd rather it not get nerfed like mech, underbog, etc.

PS- There already is a video showing how to do it, and is where I got my inspiration.

They can't nerf it.. at least, not under the same premise that Mech and such was nerfed because the farming is completely legitimate. Besides, if they were to nerf it, they'd have to nerf mage and pally aoe tanking as well.

They nerfed Slave Pens when it was entirely legitimate.

This will get nerfed.

Try the local bar.

Mana Tombs
UB(with Magic Candles)
Mech is probably still do-able, but harder

Youtube to find how-to videos.