You could probably use a brass tube with the inside diameter sharpened. Just take a tube of the size you need, and a sharp #11 X-acto knife, turn the inside of the brass tube so the edge sharpens the ID of the tube. Be careful once it's done, as if you do it right, that tube will cut nearly anything a knife will. Point is make it sharp. Use that and gently place it where you want the hole, and just spin it with a little bit of pressure, and you should get a clean hole. You might get a little dust in the wing, but hopefully if you do it right(or luck out more like)... the plug from the hole will end up inside the brass tube... and walla you have a hole. That technique works with virtually any size brass tube, and you can cut extreme angles for pushrod exits/etc... usually best in balsa or foam... but it works like a charm when you practice it. I actually have several sizes of brass tubes just for such applications. They work wonders... crisp and clean holes.
Stay away from drill bits for such work that you're talking about. Drill bits definitely have their place... but they don't work well for what you're needed.. all a drill bit would do is shred a hole into your wing... and yes.. at that point you'll have balsa dust in there. Give it a try. Good luck.