It took a few minutes for the panic attack to subside after reading your post.
I have been shooting a 209x50 cal barrel on my G-2 since January with Pyrodex RS.
I have not done a black powder cleaning of the frame in all that time.
I immediately took the barrel and stock off and can see no residue on the mechanism including looking down into the hinge pin area.
I will now remove the recoil plate and clean under it.
In the past, I have wiped a little residue off the recoil plate and cleaned that with Hoppes.
That said, I would clean the Contender like I clean any other BP firearm: Hot soapy water and rinse with hot water, blow dry with compressed air and lube with a spray silicone oil.
Of course, the barrel is cleaned seperately after removal from the frame.