The missus only uses it for no.1's ( I have a hospital bottle ).
If we are in the bush where there are no toilets, it's a hole dig for both of us....if you're gonna tip the contents of a dunny in a hole, you may as well save the trouble and use the hole in the 1st place !!
If the wife is not keen on a hole, take a pop up shower tent and one of those seat things ( with a dunny looking seat on it ).
As for no.1's, it gets tipped out anywhere ( usually behind the van )
Don't worry, it took a while for the missus to get retrained for bush crapping, so even if your missus baulks at the idea, after she likes the bush camping idea, she'll eventually take to the bush crapping idea.