Almost. You can't gain much more xp because in upper levels all enemies give 0XP, but more equipment, scrolls, potions, rations... you can save everything in the skull door of the Goo room, and do it again and again.
I don't recommend, makes the game boring, i'm sure. I've do it 1 time and last.
Depth 11 with 22 healing potions, plate armor +4, detection ring +4, strenght 16, Wild longsword +2, tons of other potions and scrolls... and exp level 16.
Too easy= Simply boring :S