I use a 5 gallon bucket, put in only about 1/2 to 1 gallon of blasting grit at a time and add WARM water. Stir it around real good, pour out the oily water, repeat with more warm water about 5-6 times and that has worked well for me. The side of the bucket and my arm were covered in oil (came off easy later with some Dawn dishwashing detergent), but the grit itself was now clean. When I filled up the tank, there was still a very slight sheen on the surface, but a paper towel slurped it right up and I have never seen anything more after that.