Keep sps away from FW for sure. I do same as reefes pieces for mixing. Rinse 2x as well, both in tank water. I cut 3 used gallon water jugs in half for dipping so I can toss them after. Wear gloves then and pour used water around my house were no kids, turtles or dogs can get to.
It works for sure, but I'm tired of dealing with it and stressing on contaminating things. Trying a different route now.
Here is just a few dipped while breaking my tank down to battle AEFW:
20180809_122546 by
matthew schueneman, on Flickr