What is the absolute dirtiest job in the military?

I know that being a mechanic can be rough and dirty at times, especially during a deployment when your working 12 on and 12 off trying to keep convoys and security teams on the road. Burning crap is one of the worst details to be on as well.

Auxiliary Machinist Mate on a submarine - responsible for maintenance of the sanitary tanks, pumps, valves, etc. Poor sods have to enter the tank and perform procedures while wearing protective clothing and air masks, and still smell for a week after a good scrubbing.