Heya Bilby
When we went bush with no flushing loo/laundry, I used to wipe off as much poo as poss with loo paper (we had the red PeaPods so all nappies were fleece lined in black - mwooohahaha!) and/or use a squirty bottle of water to 'squirt' the rest - not AS effective as a LS but still ok. Also did loo paper inital bum wipes for the bulk of it, then tidy up with a wet wipe.
Next option was if there was a flushing loo, to hold and flush - honestly it's no worse than anything else you have to do with nappies and gets the bulk of the poo off, bonus

Hold the end of the nappy same as if you were using a LS, and flush.
Either of those two methods will substantially reduce what quantity of poo is left on the nappies and at the end of the day in the washer would be no worse than someone's skid mark undies/knickers, vomit on a shirt etc etc
oh yes... I took flushable liners but forgot about them lol
HTH