you just cut off workable section about 6 feet,all about the same size diam. wise and rinse them out good with hose.
them ya take a long thin limber stick and poke a tiny hole by the opening of the gut and push the whole thing inside out and wash again.
when you get most of the junk off and lightly scrape any fatty residue/ meat away, you soak it in a salt brine.
this kills alot of the bad stuff, and helps it cure.
then after a day or two in brine rinse again and slice the gut into 3/8 inch or so strips. ya should just fold it in half split it , and then fold that half and split it. this will yield 2 ,2 ply strings.
then i would hand a weight from a nail in rafter in a dry place with air flow to stretch and dry...DO NOT TWIST.
AT THIS POINT YOU ARE JUST DRYING IT TO STORE!
then i just throw it in a piece of pvc so critters dont get at it and it stays dry, till you want to rehydrate and make string/cordage.
then make your string.
mbg