I did all the braze-one on my frame last night, and since there was flux at some point on the frame from head to tail, I decided that a hot water soak in the tub was called for. All tubes that don't intersect with the BB (plus the head tube, natch) are sealed.
Soaked the frame for a bit, worked any remaining flux loose with a brass wire brush, and then dried it off and left it for a bit. There's now oxidation (very light rust) inside the BB shell and along the lug lines...is there a secret to how to de-flux frames without getting rust? Any easy way to remove the rust?