Trying to remove something (sandblast grit) with something (air or solvent) requires that the something that is being removed (sandblast grit) be suspended in what is removing it (air or solvent). Massive amounts of the remover (air or solvent) is better at removing something especially (as is the case at hand) the thing to be removed is not actually soluble in the removing media (sandblaster grit is not soluble in air or any type of reasonable solvent).
Therefore, the more volume of the removing agent is a good thing.
Water is cheap and non-toxic. Use a lot and it will remove a lot of grit especially if you "wet" (lower surface tension) the water with soap/detergent and use directed pressure.
The water itself is easily displaced by HP air or wiping with a solvent coated rag. Using 5 gallons of MEK, acetone, or lacquer thinner is expensive and leaves a dangerous mess. 5 gallons of water can go down the drain without blowing out manhole covers for 10 blocks down stream.