The string and magnet method works!
I used the string and magnet method to snake a wire up the mast of my ODay 25. The mast was on sawhorses at the time. I took the masthead casting off, then tied a nut to some nylon string. I fed the string from the top of the mast and used the magnet to pull it down to the bottom. It took two or three tries, but worked surprisingly well. I attached my wire to the string and pulled the whole thing back up.Total project time was about an hour.Jack Jackson