The EVIL side of me says get some End-Dust, a rope and a small cat - sorry, I'm twisted!
The GOOD side of me says that many mail-order houses sell dryer-vent brushes on long flexible shafts that could do double duty here very nicely.
We haven't had to do this yet as our TT is only three years old and we don't use the furnace very much.
We have a mini-shop-vac that has a smaller diameter hose that could work really well too.
Steve & Susan
2005 28' CCD, 2011 Sierra 5.3L, Equal-I-Zer
Empty Nesters - spending our money on OURSELVES for a change!