im sure that most people here have already figured this out, but i have not seen it anywhere so im just going to say it. anyway, When i was trying to do a wash to my Sherman tank, i thinned the paint with some 5 star 100% mineral spirits paint thinner because its all i have. Now this is some very potent stuff. I tryed to apply a few layers because i was not quite getting the affect i wanted, i guess it was a little too potent, or there was too much thinner in the mix. Acctually this stuff was so string that in some places, it broke the plastic cement bonds, and i had to reglue things. Anyway. in certain spots, it took of the olive drab that i spay painted on, leavng the original surface. I found that this made for goos looking areas to be painted steal color, because the paint came off the way it might in nauture, and the surrounding area looked a little chipped. however, if you are not very carefull, you might cover up the surrounding chipped area and lose the affect.
Another thing that is probably common knowledge, is that when i did it to the treads, they lossened up so that it looks better, and in a panzer where there are no top wheels, you can use this to lossen the tread so it can naturally fall onto the wheels.
Anyway, that was just something i figured out, it may or may not work for other people, but just give it a shot on a scrap model.

Sounds like very dangerous territory, at least for me. One I'm not so sure I'd want to try out on the kits I have.
But...like with all things modeling, if it works for you, Great!

Can we see a pic of the effect?

i would put a picture up, but i dont have a digital camera, ill put some on the next role of film, the problem with it, is that if you make a small mistake on the painting of the steel, you lose the effect, which happened on one of the places i did it

I'd be careful about the effect it may have on the vinyl tracks. Anything that may effect them the way you are describing could also quicken their natural deterioration. Older vinyl tracks had a tendency to melt over the years, literally eating away at the surrounding plastic. Once the chemical reaction starts to breakdown the rubber/vinyl, I don't believe it can be stopped.

dude!!! sweet!!!! melted tracks
in that case, how do you make it so that the treads on a panzer do not stay up in the air, and fall the way they should?

Several methods I learned from trial and error and Shepard Paine's book on Modeling Tanks and Military Vehicles (Kalmbach).
1) tie thread around the roadwheel and through the upper track
2) super glue the upper track to the tops of the roadwheels
3) drill small holes through the hull and put thin wire or straight pins from the inside out to hold the tracks down in the proper sag