OP, I can feel your pain! I used to tell customers that they could save half of my bill by pulling all the wires themselves but only about 1% took me up on that since they knew how hard it is. But masts are an order of magnitude worse than other situations. You do want to run wires in the channel/conduit provided for that if you mast has one. Would not want to wrap wire around halyards inside the mast.
The vacuum idea is something I never thought of or heard of in my years of pulling wire but can see how it could help in the right situation. But the air effects would be very localized and you would have to get the thread right near where you are sucking.
Which brings up the issue of knowing where you are with your fish
, string, whatever. I can't imagine a long enough extendable fiberglass fish
rod to work on a mast but that would be great as your helper could listen as to where the end is and then try to "imagine" what obstruction might be where and try to work around it based on that "info". The problem is that the farther away you are from the control end of the rod/string/whatever, the less effect you can make on changing direction of your probing.
Last resort is to take the stick down as noted by others above, and then look at improving/replacing all existing other wires at the same time. But - I have literally spent days (on my own boat) fishing
lines through my mizzen mast and then finally got it. Persistence does not always work though.
If you do replace other wires, consider using a "signal" cable - a multi-wire cable with an insulation
sheath for the masthead light circuits. It helps keep the rat's nest problem at bay.