I also dont have hot water for my machine, so its always a cold wash. I also just use about half the amount powder for the nappies. I wash all the nappies together. i dont bother with seperate loads for differnt types of nappies. I've never had a problem with them not coming out clean after a cold wash (except for my bumgenius... dont know why but its just harder to get clean than the others). I dont usualy rinse twice. Only if theyre super dirty, but I always found newborn poo was pretty easy to get off and never needed a second rinse.

When theyre dirty I roll the dirtiness into the loo and dry pail it. Drying in the sun is really good for them as it bleaches them and they look cleaner. I try to line dry them but sometimes its just not possible and I have to put them in the dryer on the warm cycle (not the hot - it wrecks the pul.. still trying to get DH to understand this concept.)