Cold Porcelain #1: 1 cup pva glue (white glue like Elmer's Glue All); 1 cup cornstarch; 1 tablespoon mineral oil (babyoil); 1 tablespoon lemon juice, witchhazel, or clove oil (natural preservatives that help prevent mold) 1. Combine in pot. Don't use your good cookware for this because it can be hard to clean off. 2. Cook on low heat stirring constantly for 10 min or until dough forms + begins to come away from sides.
Use a sponge to soak up concrete mix in whatever shape you desire and let it harden into a hardened version of what you just cut out! Pavers or garden accents? (I would wear rubber gloves while dipping/soaking!) Worth a try.