In a normal Slave Pens run there is a vast amount of trash between the first and second bosses, with a little wall jumping this need not be the case.
Firstly, kill the first boss (Mennu the Betrayer) then slightly back track to this spot.
From there, swim around the right hand (or left, the walls are practically identical) side.
Doing this skips around 10 pulls, but also a quest NPC. Combining this guide with both:
http://www.mmowned.com/forums/wow-ex...ens-trick.html
and
http://www.mmowned.com/forums/wow-ex...lave-pens.html
can save alot of time.