Had a housefire and the cleaners cleaned my stash. I have no idea how they did it but I'm guessing it was a commercial machine. They did not treat it gently.
I want any new fabric to act the same as my existing stash. I toss it into the machine after machine-basting the non-selvage edges. If not for the fire & cleaners I wouldn't be this hard on my fabric but I couldn't see myself keeping the old separate from the new. I also know that however my quilts are treated they will be OK. (Baring accidents with critters & kids)
All this to say anything you do will work. Just be consistent in the way you treat your fabric.