A cotton dishcloth made with an H or I hook and single crochet stitches gets nice and thick. If you feel that isn't heavy enough, you can always make it double. Make your piece twice as long as you want the finished cloth to be. Fold in half and crochet the 3 open edges together.
I wouldn't advise making dishcloths out of regular 4 ply yarn, but the final decision is always up to you.