Are they similar to a feral hog?

I believe you are referring to furled leaders? If so, I have never seen a negative impact using these and the fish being deterred. I believe they give a lighter presentation of the fly especially when fishing dries.
I will say, the only negative I see if the retention of water between the strands and maybe a little more noise coming off the water.
Generally, on the Caney, I fish flouro or mono depending on what I have on me. I tend to keep the furled around and use it with flouro tippet in the mountains on wary fish.