@Loja man, were the other videos taken with the original nipple or the new nipple? What is the brand of the new nipple? In your picture, it appears to have the large opening of a Hot Shot nipple. Is the new stainless-steel nipple vented with a hole in the cone facing toward the muzzle when the nipple is installed?
Your Traditions hammer will have a notch toward the muzzle to allow the cap to fragment slightly and away from the shooter's face. Without seeing the rifle, I have to speculate that you are witnessing the venting of the nipple being directed toward the muzzle by the vent in alignment with the notch in the hammer. The water you are seeing is from the fouling, even from the modest amount of fouling from the Tripple Se7en powder, drawing water from the highly humid air. That is a good indication that a patch should be run down the bore, perhaps wrapped around a 22-caliber brush, to dry out the barrel due to the water being drawn from the air.
Since you remove the nipple when cleaning, I wouldn't use the Teflon tape, although that won't harm anything. I do recommend the use of a never seizing lubricant although a good grease such as RIG will work as well. The nipple is not being left in the drum long enough to seize up.