BBQ | beef | Cooking | Rub Rex’s Beef Roast Rub (Works for Slow Cooker, Oven & Smoker!) ByRex May 10, 2022April 23, 2026 Rex’s all-purpose beef roast rub is ready in 5 minutes and works perfectly for slow cooker, oven or smoker. Seven simple spices that take your roast beef to a whole new level.