Finger-pickers: Greasy fingers, help or hindrance?

I've noticed that when I play immediately after eating greasy food like pizza, having greasy finger tips on my picking hand makes it considerably easier to play faster songs. My fingers don't get hung up on the strings. I've mentioned this to my guitar playing buddies and they think I'm nuts. They say it makes it much more difficult to play like that because their fingers tend to slip and hit the wrong strings. I'm not a gigging player, so I don't know what it's like to play whilst dripping in sweat, but my guitar buddies say it's just the worst. Do you guys find having greasy or sweaty fingers are a help or a hindrance?