In reply to Rigid Raider:
You can wash and re-proof Gore Tex generally, though follow the care label.
Being a Scout Leader I often end up with my waterproofs stinking of fire, and I just put them in the washing machine and they come out good as new.
I doubt there is any process that would preserve the tags, though. Is it possible to carefully remove and reattach? I think however your chance of reselling "as new" is sadly lost.
Post edited at 11:05