I laminate my spars (Titebond) with 1/16" basswood top and bottom, light balsa in the middle. Very strong and light.
Never heard of balsa dowel, but I'm intrigued. I've seen people repeatedly pull wood through a circle knife jig thing to make their own dowel (Roy Underhill comes to mind). Maybe one could do this with 1/4" balsa sticks?
I'll dig around for images, but my first crack was not rewarding.
Have fun with this build Mike!
EDIT: Found a bit of info: