|I haven't stored my whole lot of diapers, but when I put my x-smalls away, I washed them in super hot water, and I gave them an extra rinse, and I hung them on the line to dry, trying to get the last of the stains out. I'm not sure if it really matters, I just thought I'd 'kill' anything if there was anything there, and then I sunned them so the stains wouldn't be there when I got them out again.
That being said, when I got my x-smalls out 14 months later for my second baby, I washed them in super hot water with an extra rinse before using them, just to get anything out again. I think I was nesting.
I don't know that it's necessary, but I don't think it hurts.