I am about to start weathering my tracks and I have read in some place that powder will give it a realistic look?
Is this true?
Probably, except the powder will most likely NOT stay in place without spraying dull coat over it, which then tends to "blow" the powder off. Best bet is to choose the color you desire (hopefully NOT red rust), from Krylon or RustOleum, and simply spray your rails.
You might also try the Advanced Search function, here on the OGR Forum, as there have been MANY topics/threads about weathering track.