So, depending on your water, your wash routine, and your detergent...you may reach a point where your diapers just don't seem to be working as well any more. They seem to leak no matter how much (or little) pee the kiddo puts in there. Well, it may be time to strip your diapers!
There are many different methods and it can really vary depending on what kind of diapers you're using. Here's the stripping I've done....
1. Bum Genius - I just rinsed and rinsed and rinsed. So, I essentially ran a bunch of loads without any soap until there weren't any suds on the top. You can also put a bit of bleach in with the load if you have the dreaded "stinkies". Here's a diaperswappers post with the BG washing/stripping details.
2. Fuzzibunz - these are what we use, and I've stripped ours a couple times. They recommend taking a brush and scrubbing a dot (literally a dot) of original dawn dishwashing detergent (the blue kind) into the cover fabric if that's what's repelling. And then putting through several wash cycles. I think I did 3 or 4, again until I didn't see any suds.
3. Other options -
A - Rockin Green Detergent - you can order enough for one soak or 2-3 loads for a couple bucks off the rockin green site. I did this on our fuzzibunz once - I didn't think it really worked, but it could on a different diaper type. You run half a load until the whole washer is full and the diapers are submersed, and then let it soak overnight. Then you finish the cycle in the morning (or 24 hours later, up to you on how long you want to soak them), and then run 2-3 more cycles without soap to rinse everything out.
B - Oxiclean - I tried this too - you add just a little bit of oxiclean to your load. This particularly helps with "stinkies" or the ammonia problem. I would do 3-5 additional cycles after oxiclean to ensure that all gets rinsed out because I think that stuff is particularly soapy.
Then, review your washing patterns to make sure you're not causing the need to strip more frequently. I always run two full wash cycles (one warm no detergent, one hot with detergent) and each is followed with a full additional rinse cycle. Some days I'll do an extra cycle without soap and a rinse to make sure that I really removed all the soap.
Also, take a look at what detergent your diaper brand recommends. Fuzzibunz recommends All Free and Clear - which is great because it's cheap. I would feel comfortable using that on any diapers - but because it's the soap AND your water, something else may work better depending on if you have harder or softer water. If you find you're needing to strip your diapers fairly often (which I would say is more than ever 2 months - I've only done mine once in a year) - I would try a different detergent or increase your rinsing/washing without detergent.