Oiling bike frame to keep it cleaner? A friend recommended that I take an oily cloth (with regular motor oil or such) and wipe down the entire surface of my mountain bike frame. He claims that it's easier to hose off after, and it actually keeps cleaner. It seems counter-intuitive to me, as I think the dirt would just stick to the oil.

What do you think? Do you do this, and does it work for you?

I should add that this is for a wet, muddy climate; the argument being that oil repels water...
I'd think that oil would repel water (make washing harder) and attract dirt. Maybe since we're in such a wet climate (Andrew and I live near each other) it's decent advice to keep the rain/wet trails/dirt of your bike but I still think that your bike would gather dirt even in the West Coast rain. Especially in areas that are hard to get at like around the seat stays and seat tube.

We oil our chains and they get filthy, even on the road. I'm not sure why it would be any different with the frame.

I can't see any scenario where that is good advice. I agree with the comment that waxing would be a better option.