I clean all my muzzle loaders once a week with a hot soapy (Simple Green) water ******, followed by compressed air and a dry patch, followed with a liberal dose of WD-40 down the barrel which is blown out with compressed air, another dry patch, another shot of compressed air and a final pass of a Kroil dampened patch...put away and never had any rusty spots. I used to use Ballistol on the last patch but I found that it resulted in a common failed ignition of the first shot, Kroil does not deliver that problem. I use Ballistol on the outside, wood, leather, etc.
I clean black powder cartridge rifles with patches soaked with a secret cleaning formula, its the same one I put through the barrel between shots, they are cleaned til dry and again given the Kroil after treatment and exterior surfaces, wood, etc. with Ballistol. Other firearms are usually cleaned with Hoppe #9, Kroil for final wipe of barrel and cylinder.
I clean more than most and am amazed at how crappy others keep their firearms, not surprised at all when people have trouble with faulty ignitions on muzzle loaders. When was the last time you cleaned that thing?