The first time our guild ran Naxx 10-man, none of us knew the Heigan fight beyond what we had read, except for one person who had done it on 25-man with the corner trick. Well, that didn't work out, and after 2-3 wipes trying that we decided to do the dance.
Even before the first teleport most of the raid was dead, and after the first round of dancing we had 4 of 10 left up (holy pally - me, resto shaman, ret pally, prot pally ... I don't think Heigan can kill a pally). We continued so the others could see how the rotation works to learn it, and before we knew it we had spent 24 minutes on him and 4-manned him down. A hunter in the raid got up, made a sandwich, came back and ate it, all while lying dead on the floor as we killed Heigan. At one point we were unsure of an enrage timer, so we had someone who was dead go look it up online ... after all, we had plenty of time.
It was epic, and actually a bit easier because we used the bodies on the floor as a guide for where to stop during each wave . I've heard he can be 2-manned with a healer and good dps tank.
Then a few weeks later, we started to do the same thing on Sapph (4/10 left), but decided to wipe it after about 12 minutes, since he wasn't going down as fast. That time it was same holy pally, same prot pally, DK and resto druid.