I have always carry a 5 gallon bucket and a break down shovel. I have the bucket half full of Peat Sorb. I toss the peat down and then scoop it into the bucket right before everyone is about to go. I have not caused a spill myself yet(probably not wheeling hard enough
) But I have used the kit twice on others.
As for disposal I burn the stuff in a wood stove(it burns hot) soil and all. I never like the idea of putting it in a landfill or leaving it out there despite them saying you can.