The way to "powerlevel" dung is to pay pro dungers to key for you. You then just sit in the home room until they finish the dungeon, and repeat. It's very expensive, though; levels 1-80 can cost about 80-100m, and from 80+ it's 30-40 GP/exp.
Well i highly suggest you get some of the lower lvls yourself get a feel for the skill before paying others for it. While doing dungeoneering there is a "party" or group of people doing the floors/levels, everyone in that party receives xp reguardless of whether they do anything. So its possible to "leach" floors , basically what everyone is saying is to find someone who lets people join their party and leach xp. A good place to find one is http://www.sythe.org/forumdisplay.php?f=286 . I cant stress enough that you should try it out for yourself with a friend or two , dunging can be a great way to get various types of xp since most all skills are included. You might like it, i for one HATE it. GL man
Perhaps an easier way, instead of buying a dung leech would be to pay a dungeoneering trainer on sythe to do it for you, so you don't even need to be present at the computer at the time of you being trained.