|Just want to add two things:
1) I rinsed all bf poo diapers (so that would be nearly every feed for almost six months, eek!), but still had vibrant orange diapers, so I don't think it helped at all for not getting stains. After just one time of line-drying outside, though, they looked brand-new again. It truly was amazing.
2) I hadn't heard that I didn't need to rinse bf poo with #1, but had by the time we had #2, so figured I'd save myself the trouble. Only he was one of those babies who went only every week to 10 days. While catastrophic in effect, his poops were not as runny, so they didn't actually completely rinse out in the washer (well, they did come off the diapers just fine, but after finding a few "clean" poop remnants in the door gasket, I decided I'd better rinse). So if you do end up with one of those, you may have to rinse bf poos off, but otherwise I completely agree with Karen--do a pre-rinse and save yourself the trouble!