grease and oil.
Good old M7
Theres also the M10 bayonet. USMC and Army Airborne bayonet.
Imho, the M7 looks like a knife, and nothing more. Good for sticking people, nothing else.
The M8 makes a nice utility knife, but not so handy as a fighting knife.
M10 is an great fighting knife, but not so useful as a utility knife.