I am a pre-washer, but if you want to pre-wash the quilt, just fold it in half with all the seams in the inside, then tack it together with a basting stitch, wash on gentle. I would line dry it but I believe you could dry it with a couple of sheets.
My daughter wanted me to replace the batting in the Christmas quilt I made over 20 years ago, and I did the washing routine to see how the holes where the ties would react.