Ok, juste found and TESTED this 8 hours ago.
Seems to be inspired by http://www.mmowned.com/forums/wow-ex...-2nd-boss.html but is not, and it doesn't matter beacause this method is safer and skip more packs.
1) Pull ICK
2) Tank him to the point before the tunnel / galerie
3) Kill him !
PS: Sorry for my non native english (please PM me any spelling/grammar mistake)
PPS: more exploit here:
4) Do not not wipe on the last boss, because as you resurrect and go back to him, the 4 pack will spawn (yeah, beacause with the exploit, the 4 pack don't spawn because they are just scripted events which make them appear when you walk/run in certain areas)
5) But, here is the interesting part, full hot your tank, take your mount and run straight to the gallerie, and they will just lose aggro.
Enjoy your gain of time !