Beats my two aces,
but I would assume about a couple of days or more, like sinew, or rawhide. I would just let it dry a couple of days, and see if it is still damp, or still really flexible. I don't really know anything about it. But I don't see why you could not use it. You might split it open, or just tack it down, and take a razor, and run it down the length of the intestine, and a couple of times, and take the strips, and twist them, and nail, or tie them down to dry, or use them wet to tie something, and see how they shrink, and how strong they are.
I'm just guessing, here, I don't know anything about fish guts for string.
You just have to experiment with it, and see how works. Let us know how it turns out. Always good to know another source of strong string, or cordage.
Wayne
