Interesting thread. I always figured the merit of blowing the smoke out of the barrel was to evacuate the barrel of smoke that would otherwise cling to the inside of the barrel, adding to fouling.
Around here, we have plenty of humid days, so much so that it seems to attract fouling to the bore wall. So I'm not sure how adding moisture is a good thing. I believe a muzzleloader that sits for 10 minutes after a shot with no swabbing of the bore will be harder to load in any situation, humid or arid.
Speaking of which, I kind of wish that the RSO would call for "swab your bore!" after every cease fire. So that once all firearms are clear, people have a minute to swab the bore before they are set aside during cease-fire. As it is, I always try to leave a minute or two before cease-fire is called so that I can punch the bore once or twice before the rifle sits for 10 minutes.
I'm not sure of the rule at my local club, but in the future I will probably keep a short section of plastic tubing handy for blowing down the bore.