Before you treat any diaper rash, attempt to determine the cause of the rash, because that will help you decide how to treat it.
If your rash seems to be caused by a reaction to the diapers themselves (redness all over the diaper area), you’ll want to reconsider your wash frequency, your wash routine, your detergent, or the diapers themselves. (Some babies are sensitive to fleece in their diapers – my middle child got a bright red rash every time she had fleece lined diapers on.)
If your rash is caused by an infection – bacterial or fungal – you’ll want to apply appropriate pharmaceuticals or herbals or other natural treatments aimed at these types of infections.
If your rash seems to be the run-of-the-mill irritated skin caused by sitting in a wet diaper too long, heat, or just general irritation, you can treat it with breastmilk (really!), fresh air, and sunlight. Wash baby’s skin with plain water – use running water if the skin is really irritated, rather than using a wipe. And treat baby’s skin with a good-quality diaper rash cream. You can use one that’s safe for cloth diapers (usually sold by cloth diaper companies or labeled as being Cloth Diaper Safe), and not have to do anything special while you’re using it. Or, you can use something that’s not cloth diaper safe and just make sure to use disposable liners between the cream and your diapers. Many families use old cut-up Tshirts and rags for this purpose. If you choose to wash these liners, do NOT wash them with your diapers.
For any rash that doesn’t seem to be responding to regular diaper cream within a reasonable amount of time, or that worsens instead of improving, you will want to consider seeing your child’s doctor. Some rashes warrant a doctor’s opinion.