Smoky BBQ Beef Brisket

I've only made this once. My crock pot is bigger so next time I will double the recipe for the sauce so the beef is covered entirely. Russell says we should keep this one.

2-3 lbs. brisket
1 t. chili powder
1/2 t. garlic powder
1/4 t. celery seed
1/8 teaspoon pepper
1/2 cup ketchup
1/2 cup chili sauce (I had Frank's Hot Sauce)
1/4 cup packed brown sugar
2 T. vinegar
2 T. Worcestershire sauce
1 1/2 t. liquid smoke (I left out)
1/2 t. dry mustard
1/3 cup water
3 T. flour

Rub brisket with chili powder, garlic powder, celery seed and pepper. Place in crock pot. Combine ketchup, chili sauce, brown sugar, vinegar, Worcestershire, liquid smoke (if using) and dry mustard. Pour over brisket. Cover and cook on low 10 hours or high 5 hours. Remove meat from cooker and skim fat from juices in cooker. Stir together water and flour and add juices. Cook until thick and bubbly. Serve with meat.