Line the nappy with a liner from Woolies, or chux cloths cut in half work well too. There are flushable liners available from some places, but they are a bit more expensive.
When you change the nappy, rinse it and pop it in a lidded bucket. You don't need water in it at all. Sprinkling a bit of bi carb over each nappy when you put it in will help stop it getting too stinky.
Try to wash every day/every second day. If you leave them too long the wee will ruin the nappies.
Tip them into your machine and do a cold pre-wash or pre-rinse (no powder). Wash them in a cold/cool/warm wash (not hot - it will ruin the waterproof cover) with half as much powder/liquid as you normally would for a load that size or soapnuts. Don't use fabric softener as it will clog up the nappies and stop them being absorbent. Do an extra rinse when the wash is finished. Also, don't use bleach or vinegar because that wrecks the waterproof covers too.
Dry in the sun whenever possible.
If your nappies get really stinky or start leaking, do a strip wash. In a top loader wash them in hot water with a squirt of dishwashing liquid. Keep rinsing until all the suds are gone. Don't do strip washes too often though or you'll wreck them! (Not for frontloaders!)
Oh, no zinc based bum creams either, they also clog up the absorbency!
I hope that helps smile