It may be easier as Frost or Unholy, but it is also quite doable as Blood.
Generally, my method works like this.
1.) Tell the dps to hold their fire until you're situated on the middle platform. It is hard enough to generate aoe threat on the move, if people try to jump the gun it can get out of hand easily. The tunnel does not demand the hardest dps they can manage as fast as possible, but people get excited...
2.) Mount and hustle to the first pair of adds. I usually prefer to IT on the way in, then PS one target, and usually hit a HS on the second target before I Pest, actually. Once the first two little mobs run up, Pest the diseases from the first target around, and keep hustling.
3.) About this point when you're still a short distance from the middle platform I will use IBF and/or avoidance trinkets, or possible Vamp Blood if you have Mark of Blood and/or Rune Tap to combine with it. Your goal here is to require as little healing as possible so that the healer generates as little threat as possible.
4.) As soon as you can reach it with range, drop DnD on the middle platform and collect everything on it, and commence aoe tanking the way you would anywhere else (matching the HS/BB balance to the group and their AoE/Single target dps strengths).
5.) The top half of the tunnel is generally smoother, and it's smart to keep juggling diseases out if you can.
The big thing is, don't be shy to stop and collect things mid run. It is better that everything is stuck to you than that you get to the platform immediately. Save your Death Grip and taunt for things that come loose, don't waste them when new things are running in. Just smack newcomers with a strike or auto-attacks, and keep diseases around.
Don't let yourself get excited and try to rush beyond the pace at which you can keep things under wraps.