Stripping means to wash with a product that is meant for removing build up on a fabric. It removes dried in mineral deposits and detergent residues, leaving fabrics brighter and more absorbent. Stripping does not mean bleaching, washing, or laundering with only water; these things can help with odors, but generally are not enough to remove baked-in residues. Stripping will help with odor issues and absorbency issues with cloth diapers. It's also great to do your kitchen rags, towels, those shirts with the perpetual armpit stink, chef aprons and pants, and more!
Build up means your diapers have a film coating the fibers. You will notice this because they may come out of the washer and dryer smelling and will lose some absorbency. Sometimes diapers smell clean when washed and dried, but have a distinct odor when the child pees in them. Detergent residues can trap bacteria that cause odors, making it hard for bleach to fully penetrate the fibers. Pocket diapers and all-in-ones that worked great when new may begin leaking (this can also be due to a child's urine output increasing, so keep in mind that you may need to at more absorbency to the diaper). Don't worry! It's easy to strip them!
If your diapers are smelling, repelling, or wicking, then chances are that the detergent is building up. Diapers may also be smelling due to bacteria, in which case stripping them will not remove the bacteria. In this case, we recommend stripping them and then using 1/4 cup of bleach in a wash, or using an oxygen-based bleach according to our suggested protocol.
To keep cloth diapers working their best, we recommend stripping them once a month. If a cloth diaper incompatible detergent has been used, then we recommend stripping all your diapers twice, and then switching to a compatible detergent. Some folks with very hard water strip more frequently; sometimes people use diapers for a year without know what stripping is! We love preventative care, thus feel it is best to pick and interval that works for you and this should prevent issues from arising!
Start with clean diapers. Use 1/2 packet of RLR (this is our favorite) for a top-loading washer (1/4 to 1/3 packet for HE machines) or 1 capful of Sensi-Clean on a warm cycle to strip your cloth diapers (use 1/2 capful for HE washing machines). For cloth diapers with a lot of build-up, repeat. Then rinse, rinse, rinse your diapers to remove any RLR or Sensi-Clean residue, along with the detergent residues being removed. Rinse until you no longer see suds in the water. Dry on medium heat.
Sensi-Clean (also labelled as Sports-Wash) is biodegradable and is made from vegetable-based surfactants. A very small percentage of babies are allergic to Sensi-Clean and will develop a severe rash after its use. For this reason, remember to rinse the diapers and watch your baby's bottom closely for any reaction.
Alternatively, you can use 1/16 - 1/8 cup of Dawn Original dish detergent instead, although we have not found this method to be nearly as effective.
Ideally, yes! Unless you know that the diapers have just been stripped before you obtained them (it's still worth asking how they were stripped, as there is often misunderstanding as to what this means!), this would be the best practice. It will help you start fresh, and if an issue arises, you will more easily be able to troubleshoot it. Not everyone is aware of the best practices for washing cloth diapers, thus you can never assume that a previous owner followed suggested care.