Like I said, for the really nasty, loose stuff people would just throw an open bed trolley in the back of a different vehicle and do it that way.
I don't know what you carry, but I'm pretty sure you can do both of those things in a van if you have to. At most you may want to put a tarp underneath first. And you can hose it later. Again, I don't think Americans are picturing what the back of a work van looks like or how it gets used. If you fully open the back and side doors at once you actually get direct access to more of the floor than you do in a pickup bed.
Like I said, for the really nasty, loose stuff people would just throw an open bed trolley in the back of a different vehicle and do it that way.
I don't know what you carry, but I'm pretty sure you can do both of those things in a van if you have to. At most you may want to put a tarp underneath first. And you can hose it later. Again, I don't think Americans are picturing what the back of a work van looks like or how it gets used. If you fully open the back and side doors at once you actually get direct access to more of the floor than you do in a pickup bed.