I understand and agree with what Dan has noted above. Humidity has a lot to do with how the fouling builds or wants to. here, we will have humidity from the high 90's to low 30's even in the same day. Just last Sunday, there were 3 of us on the range, walking the trail in about 1 1/2 feet of snow- sure wish I'd taken the misery slippers. Luckily the snow wasn't as bad in the tight bush where the trail is, but getting there from the club-house was another thing.
When we started off shooting, the fouling in the pan and on the barrel was black and wet due to the high humidity, but 2 hours later, the fouling in and around the pan and on the barrel was as white as the snow as the humidity had dropped to the 40's. Hatchet Jack & I were using LHV, while friend Len used a concoction of windshield antifreeze, alcohol and some other ingredient. None of us experienced any change in loading from the get-go to the end of our shooting. No one had to wipe the bore once, nor did we notice the humidity change other than the colour of the fouling.
Our normal routine, is to walk up to the 'stake', prime & take the shot. We then step back to allow the next person to shoot while we watch the shot and reload. After all have shot, we advance to the next stake with a loaded rifle or smoothbore but unprimed pan, step up to the line in turn, prime and shoot. Out of 50 shots at ranges from 20' for playing cards, to various gongs out to 104 yards, I think I missed 3 targets. I hate trying to split cards. Lack of wiping didn't seem to hurt my score as it's the best I've shot in a long time. My shooting improved due to changing the breech system in my rifle to a solid tang, from a hokey stud projection on the tang fitting into a socket bolt for the actual plug, but that's another story.
As to Seven's test, how much of the charge didn't ignite, % wise. In Taylor's test in an actual steel barrel, loaded and left outdoors for 5 days, there was perhaps 2gr.(maybe less) of powder that had stuck to the patch. The rest poured out normal powder. The powder stuck to the patch wasn't wet due to drying somewhat- apparently. Perhaps the rest of the powder absorbed some of the 'moisture' from the LHV, however it was dry and flowed as normal. His test was to determine whether or not the LHV would protect the bore from the muzzle to the charge and whether the LHV would cause rust to build where it sat underneath the ball. The test appeared to be conclusive as the humidity ran from 100% to about 30% during the 5 days of the test, and from temps of 4C to -15C. No rust and no fouled powder which was a happy finding.
When I hunted the late special weapons moose season, in temps ranging from 3F to -56C (about 40F to -65F), I needed a lube that wouldn't become too stiff to load (ball punches through the patch at the muzzle) and would allow 2 or 3 ACCURATE shots without having to wipe. I ended up, after a few years of different substance trials to using Mink Oil as sold by Track and paper ctgs. The previous year, I used baby oil which allowed up to 2 shots, reloading getting crunchy for the second shot, then it needed wiping. If you need a fast second or maybe even third shot, you don't want to have to wipe the bore. Now I hear, "I" only need one shot! Well, if you have to shoot through a sea of willows, or aspen branches - there is never an open shotoing lane - sometimes you need more than one shot. What do you wipe a barrel that's minus 40 degrees with, to soften the fouling? I ended up testing and becoming to like paper ctgs. as in the big bore, they gave identical accuracy to a patched round ball, yet were easy to load for up to 10 shots. Mink oil lubed patches allowed 3 or 4 shots before wiping was necessary. Although the patches were pretty stiff in the bag, as soon as you touched them, they became soft and loaded just fine. The humidity at -40F is very low - in the 20's I'd estimate. I suspect that particular hunt at -65F, it could have been even dryer. Yeah, it was a mite fresh.