I've done it a few times. As a matter of fact, yesterday I added used sand to my new 180 that I am setting up. After I put the sand it, I added 60 gallons of salt water. I've stirred it up a bunch of times yesterday and today. Tomorrow I will remove the saltwater and add 60 gallons of new salt water. I will continue to do this until all the tests (ammonia, ph, nitrate and nitrites) are at 0.
Joyce