Well, most of this stuff sounds a bit modern to me!
...and if someone finds a bag of condoms in your bag, and your hunting out in the wilds with only animals about, they mght start to wonder about you....
I don't normally use a muzzle cover any weather, but if it's Real bad, I have a 'tompion' made from a little ball of oiled wool, wrapped in a bit of blanket, and tied off. this sort of resembles a raddish with the leaves on (!)...and can be pushed into the muzzle, leaving the 'leaves sticking out.
If you raise gun to fire, the 'leaves remind you it's in the bore.
(most times!)
I did once shoot one out, and it was no bother at all. with the air pressure, it must have exited the bore before the ball cought up!
Richard.