absolutely. When I got my new b17, we had a heat wave going on, humid like anything too, and so by the end of my initial hour long rides (about all I could do before my sitbones were too sore) my bike shorts were soaked, and the leather had gone all dark from being wet--so in my opinion, this greatly helped it breaking in (and goes along with the anecdotes of riding them in the rain and them being "broken in" afterwards; or putting a wrung out cloth on the sitbone area while riding--pretty much what my sweaty rides were doing)

sasq, on the used one I bought, the leather was thicker, so it flexed less. After riding on it a reasonable amount, it was ok, but I ended up putting Proofide on it again, especially on the sitbone area, figuring to soften it up a bit just in that spot--this helped I found. (I had done that towards teh end of breaking in the new one, when I was getting a bit sick and tired of it still being uncomfortable, I think it helps putting it on the localized spot (I put it on the underside as well at that area)