I've done it a couple times, from what I've seen they recommend doing it on a warmer sunny day and run it as fast as possible.  There is almost nothing on the ground when running it like that, you can smell it in the air so I'm sure some is lost to evaporation, I've only used very cheap fungicides as I wasn't very confident  in it.  Unfortunately the two years I did it there was no late season diseases, the last couple would have been great tests but we were already to wet and I never ran it to smash down my tire tracks.

I tried some foliar fert as they provided it for free, wasn't able to pick it any changes in the tissue samples.   I wouldn't waste the time or money.  I can't get biologicals to show any response when applied perfectly, not gonna waste the money on them fertigating.