It is recommended that you wash your diapers every two days and that, between your laundries, you keep them stored in a waterproof sac or into an open vat. There should be no odors.
For an exclusively breast-fed baby, there is no need to rinse, as the stools dissolve in the water. But if your baby drinks infant formula or began to eat, you need to take the stools off as you go before you put them into the sac. Several options are available to you: you can use disposable (flushable) liners, washable liners, or simply rinse in the toilet or in the sink.
Begin with a rinsing cycle. If you wish, you may add clothes in the machine during the normal washing cycle. Wash in cold water, with the recommended soap quantity by the manufacturer. Finish with an additional rinse cycle. Accumulation of soap in the diaper may cause irritations to your baby and release odors.
Inserts can be dried in the dryer, at high temperature. As for diaper covers and all-in-one, though, it is preferable to hang them or to dry at low temperature, in order to preserve elasticity and waterproof ability.
Stains may appear on diapers. This does not mean that they are not clean. If you still wish to get rid of them, the more efficient and less damageable way to make them disappear is to hang them in the sun.