I’m busy making a crochet rag rug from an old sheet and some caravan curtains bought in a charity shop.
I tear the materials into 2 inch wide strips and join the strips together, winding them into a ball. I use a 7mm crochet hook. This may seem like a small size hook for the thickness of the “yarn” but it does work as you only need it to pull the yarn through. The stitches are worked much more loosely than in normal crochet. It’s quite hard on the hands but I’m gradually getting better at it.
If you are interested in crocheting rugs with fabric this book, “Crocheted & Fabric Tapestry Rugs” by Diana Blake Gray is very informative. (I think I found my copy on Amazon).