5 full days in Malekula

From Oct 23-29 I'm visiting a friend teaching English on Malekula as his Peace Corp assignment. Since I fly in on the 23rd, and fly out the 29th, I only have 5 full days. We wanted to do the ManBush walk, but I think that requires a minimum of 5 days. That's cutting it too close. I'd love to be able to see some of the Nambas and their dances, and I see there are even 1 day trips for this, but I"m afraid it will just be too touristy. Is there any way to visit any of the Nambas without showing up with a tour?
We're both up for walking, though I don't want to have to carry a tent. Any suggestions for something adventurous that I can do in the short time I'm there? We're both low budget, but I can afford to splurge if need be.