Old trick from my magic hat. Cut a rag into a square that you can ball up to a jam fit in the seat tube. fold one corner and tie a strong string to it securely. About 3' out tie a nut to the string. Soak the rag in oil ball it up and push down the seat tube below the work area with a stick, tossing the string and nut in after it. Do your work above the rag, and when finished, flip the frame over so the nut falls out, and pull the rag out by the string, wiping up any chips and leaving an oil film on the tube.


Of course this won't help on the down tube. OTOH, if you have a cartridge BB, the chips don't matter anyway.