Whisk together soy sauce, hot water, Worcestershire sauce, liquid smoke, onion powder, garlic powder, cayenne pepper, Creole seasoning, and Cajun seasoning in a microwave-safe bowl. Microwave for about 1 minute; stir well. Add roast beef and toss to evenly coat. Cover the bowl with plastic wrap; marinate in the refrigerator, 8 hours or overnight. Remove meat from marinade and rinse with hot water.
Preheat oven to 160 degrees F (70 degrees C). Place a pan on the bottom of oven to catch drips.
Place meat strips on a rack about 1 inch apart from each other; dehydrate in the oven for 5 to 6 hours, or until desired consistency is achieved.