I spoke to a sales rep at a local outfitter today, part of the conversation leaned towards my gear and this came up. My bag is a 1983 WM summerlite and I know it has been cleaned in the past but maybe 70 uses ago and the loft seems to have suffered over time.
His suggestion is; using nik wax for down bags, fill the bathtub 1/4 full with warm water and cleaner, wash the bag thouroughly and rinse a minimum of 2x. Next he said I can use the clothes washer, using the spin cycle to work out some of the extra water. Then using low heat in a clothes dryer and using about 6 tennis balls to work the feathers from bunching, dry the bag.
Anyone else to comment? does this sound safe enough not to compromise the down power?