There are several solutions around. It is a matter of heating the barrels, applying the solution and then carding the barrels. They all seem to work.

Dixie Browning solution:
http://www.dixiegunworks.com/product_info.php?cPath=22_96_214_216&products_id=3054

Laurel Mountain:
http://www.dixiegunworks.com/product_info.php?cPath=22_96_214_216&products_id=3175

Birchwood Casey Plum Brown:
http://www.dixiegunworks.com/product_info.php?cPath=22_96_214_216&products_id=3167

You might also want to read some of the following:
http://www.americanlongrifles.com/WorkShop_Barrel_Browning.htm

http://www.laurelmountainforge.com/barrel_brown_inst.htm

http://www.hobbygunsmith.com/Archives/May04/AutoShooter.htm

Be aware that a lot of what is being talked about is browning fluid steel barrels for black powder firearms.

Pete