I can't find that these Dayak daggers has been discussed on the forum before?
On the Sadop there isn't much information in the litterature.
The Dohong is a ritual dagger that's mostly used in funeral ceremonies.
There are a lot of rumours about it, both because it's quite rare and because it has been mostly for ceremonial pusaka "magic" use as long as outsiders has visited the inner Dayak tribes.
I have gathered what I have found about them at this page and hope that maybe someone could share some additional info and comments?