TE, there is a regimine for the cleaning of double rifles, but what i think you are asking is about the cleaning of the bore! If that is the case, then the only thing I would suggest is, always clean from the chamber end. Beyond that care must be taken not to cause undue wear at the muzzles. In the smaller chamberings, a regular rod is uaually all that can be used, but if the rifle is 450 or larger, an approperiate shotgun cleaning rod made of wood is the best. Galazan has little two piece wooden rods for a 410 shotgun that works very nicely! For the bore guide, if you have, or have a friend who has a wood lathe, have him turn you one from a stick of NYLON, useing a cartridge case as a patern.

As Mike says, one shouldn't get the barrels too clean, unless wet weather is in effect. A slightly fouled barrel set, seems to regulate best.

The one thing that should be done at each cleaning is, to clean the hook, and pin area very throughly, and coat with a thin coating of plain vasaline. Most doubles that become "OFF FACE" do so from wear in this area, rather than shooting them.