My suggestion for the metal:
Wipe off the initial bits with some shop towels combined with some elbow grease.
Move next to some steel wool. 0000 will work perfectly but I have used 00 with good success against stubborn bits, rust...etc without harming the finish on the metal or bluing. I have not tried this on anything parkerized. I think it may scratch the finish on anything parked so you may wish to omit this step or try a little bit on an inconspicuous part.
Finish off by rubbing some oil with a fresh shop towel.
For the wood:
I wipe off whatever I can with a clean shop towel then apply some oil and rub it in with another clean shop towel. It has worked quite well on my milsurps.
For stocks that had mud, dirt, grime..etc on them, I washed and rinsed them off in hot, not boiling, water. I then wipe them dry and apply the oil step mentioned before. This has worked quite well on a vet bring back Gewehr 98 that was just covered in mud.