Yes it mixes with water but it doesn't suck it out of the air. And in fact if you clean a black powder gun with "moose milk" made from Ballistol in water the water content does a fine job of removing the fouling and afterwards the water in the MM dries away and leave ONLY the oil behind. Which then protects the steel just fine.
Thats what ive found also.
IMO the ballistol is WAY to strong straight from the bottle i like it watered down a little. It still cleans well and isnt as oily its weird.
I have a seperate bottle i take with me in my range bag that has a mix of water and ballistol and i use it when i notice enough fouling that my guns bind up.
The moosemilk mix thing reminds me of G96 that stuff cleans simmilar and leaves an oil behind but im trying a different cleaner to see if i can mimimize the binding from the fouling. I like the G96 but it might be petrolium based wich people on here said isnt good with substitutes
Thats the thing about black powder you are on a never ending quest it seems like. I have a favorite gun (Remington) i have a favorite powder (swiss or T7) a favorite cap (remington #10) a favorite ball size (.454) and a favorite load (20g) everything else i think im still searching for. Im getting closer but there are still missing pieces.