I did the job when replacing valve seals as well in Jan/Feb 2013. I ended up going to a gas station that had diesel, and pumped a few cents worth of diesel into a container.
When I popped my rocker arms, 2 of my lash adjusters fell apart, so if you plan on doing this job, expect to need to replace a few of the adjusters. it isn't too expensive to replace them all.
I used a paperclip to trigger the thing inside the adjuster to allow me to fill it with diesel. When I did fire the engine up, it sounded REALLY bad, but quickly the ticking went away and turned into a smooth 3.5L purr