I have one, and it technically can go infinite. It's just crazy slow so I haven't made it far yet. It also seems to get laggier the further I go so it get even slower because of that.
You need 4 items, the last one having a few variants: berserker's club, hourglass, candle and peridot. Peridot can be substituted(and improved) with poison whetstone, smith poison buff or belt of knife.
Add some recovery(gemstone heart) for the occasional unavoidable spikes damage.
In case you haven't understood yet the idea is to get infinite attack in a single turn with berserker's club. You avoid killing yourself with the hourglass which negate any damage you would inflict to yourself. You deal damage by adding poison to the club. Since you stack enough poison on the enemies so they die as soon you end the turn it never come back to you so you can not die to the self inflicted poison.
I just made it to floor 19 and I have -7611 damage on my club.