I would recommend one of those Wet/Dry vacs that the local Supermarket rent out.
I don't have first hand experience w/ them on my vehicle, because I don't allow eating, I don't have kids or a dog.
If my memory recalls...I think my parents once rented them for the house.
...change of subject...
Weathertech or Husky Floor & Cargo Liners will solve half our problem next time around.