I purchase yards of the heavy denim, about .018. I take it home, cut it into strips about 2" wide and as long as the material is wide. I roll it up and place in my shooting box or bag and when shooting, I put a little moose milk on it, load and shoot. Never wash the material. I don't do spit patches so I'm not sure what it would taste like with out washing.
For hunting, I use a little bear grease on a few cut patches and run a piece of monofilament line through about 10 or 15 of them down the middle. Tie a knot in one end and the other end on my bag strap. When I load, I just pull one off of the knot, pulling it through the patch, load and fire.
Mike