I like your 25ft custom made "probe". There are commercially
available thin fiberglass poles that electricians use for fishing
wires and such. Might be too expensive for a one time use.
http://cableorganizer.com/fiberglass...oping-pole.htm

Lucky for you that you have holes in both ends (root and tip) of the
wing. I assume that the tip holes are for winglets.

I am not so lucky. What isn't clear to me is how the strings for my
bags are routed. Do they loop around some fitting inside the wing and
back to the wing root hole?

- John