You would have to use a cold dye, as a hot washing machine dye needs to be boiled in, so you would end up with the heat of the water wrecking the filling of the sleeping bags. Also, if the bags are made of nylon/man made material mix they won't take a dye very well. If they are cotton, you would be able to cold dye them.
A day of all things motorhome and campervan. The show is held both in the main indoor arena and across the grounds. Catering, hot drinks and food options are available. Easy access to the site and free parking included. Win one of five pairs of day tickets