Have you tried the extra long Q-tips that are used in doctor's offices? You can get them at most surgical supply stores - my family owns a cleaning business and they order them by the bundle. You should also look into purchasing any number of mini-vacuums that have lengthy mini hoses -- the better ones are online (I have seen them at small novelty stores but nothing at any stores like WalMart or anything like that). Here is an internet link to a company that sells several different mini vacuums and hoses. http://www.nextag.com/mini-vacuum-cleaner/shop-html
Other than those few suggestions, you are most likely looking at a very long feather duster if you can find one that is long and thin enough.
I hope that helps. THANK YOU !!