You don't need to use vinegar in the wash although it wouldn't hurt anything (and is often used in the rinse cycle). I would take the quilt to a laundromat and use their largest front-loading machine. Orvus is a very gentle soap to use. It's actually horse shampoo and a lot cheaper if purchased at Fleet Farm or other farm supply store than in a quilt shop.
I believe the vinegar would be used on a white towel and rubbed across the cat claw holes to close them.