Descending into the deepest crater in the world is not for the faint-hearted and it will take a full day from the rim down to the base of the crater, one day exploring the crater and one more day back out. Together with the normal two days hike this option takes at least 5 days. During the 3 days in the crater, the porters get paid double wages.
Only few have traveled the treacherous way down and you are obliged to hire an experienced local guide. By deciding to go down into the crater, you have automatically signed the waiver. Rescue is very difficult and at your own responsibility this is considered an extreme adventure!