I've done this as a survival hunter several times for my guild's 10-man Naxx raid, and it can be pretty easy once you find an effective kiting path around the back of the room. The key thing is to find a way to run in a straight line as much as possible in order to get away from the zombies already pursuing you (as they'll catch up pretty quickly if you're constantly turning), but to not get too far from the spawn point on the middle grate so you can still pick up new chows.
I eventually chose a figure-eight sort of path with the center at the spawn point, but I waited until I ran past the grate to shoot any new spawns with explosive shot or multi-shot depending on how many there were. It usually didn't take much more than that to get them on me for the duration of the kite (and this is with two healers supporting me, as I appear to have acquired a reputation for being insane and getting myself killed =P), and once the Decimate timer ticked down to about 10 seconds, I grouped them all up to the back of the room (right behind the spawn point, ideally, so new spawns would join the main group in approaching Gluth) and popped Deterrence. This way, they would all move towards Gluth as a unit and travel the longest distance possible before they got to him - translating in more time for us to AoE them down.
The figure eight didn't have me dropping frost trap all the time, but I did use it heavily to give myself space. I'd also point out that ass-charging (i.e. turning your character around midjump and using Disengage) is an excellent way to get distance on your undead entourage.
With enough practice I could see this done in 10-man with only two people: hunter and healer. Heroic Naxx I have very little experience with (yes, laugh now), but I imagine doubling this (or even just taking two hunters, depending on how good they are at not getting hit) should be sufficient.
Hope this is helpful! =)