I just had a similar thing happen to me on a commute home the other day with a brooks pro (didn't have a bag, wasn't raining when I left work) - I wasn't in the rain for anywhere near an hour, and the saddle didn't have much more than 400 miles on it, but after air drying it was perfectly broken in. Not exactly a method I'd suggest for break-in, but certainly no harm done. I didn't mess with the tension and I did put the proofide on when it was dry. I've ridden it since and I couldn't be happier with the result - it's now the most comfortable saddle I've ever ridden - again, not that I suggest this method of breaking-in a brooks saddle...