Cultural experience in Vauatu and Land diving

Dear Fellow travellers,
I´m thinking of going to Vanuatu by the end of April. Basically to wittness the land diving ceremony in Pentecost.
The fact is that I am very interested in Anthropology and would like to focus my trip on a more cultural aspect, with the aim of mingling with the locals, specially were tribes, ceremonies etc are held, and observe all their kastoms and interact, learning from them.
I would appreciate if you could give me some tips of islands or places where i can find all this (even homestays) in Vanuatu, as the trip is so expensive that i wanna make the most out of it, and achieve a great cultural experience (if possible non turisty).
Also How much time would you reccomend to spend in Vanuatu?

Thanks in adavance for the help!

Hi - I know it's a bit late, but I'm pretty sure this runs every Saturday until the end of May if that helps.
You can fly there with AirVanuatu, either do a day trip or stay overnight.
We are doing the daytrip option in a few weeks.