Cook bacon in a Dutch oven over medium heat until crisp; remove bacon, reserving 2 tablespoons drippings in pan. Crumble bacon, and set aside. Saute onion, celery, and garlic in reserved bacon drippings until tender.
Drain clams, reserving liquid; set clams aside. Add reserved clam liquid, potato, and bottled clam juice to vegetable mixture; stir well. Bring to a boil; cover, reduce heat, and simmer 20 minutes or until potato is tender. Remove from pan, and let cool slightly.
Add butter to pan; add flour, and stir until smooth. Cook over medium heat, stirring constantly, 1 minute. Gradually add half-and-half; cook over medium heat, stirring constantly, until mixture is thickened and bubbly. Add potato mixture to white sauce in pan. Cook 5 minutes, stirring frequently. Stir in reserved clams, salt, thyme, pepper, and hot sauce; cook 1 minute. Ladle into individual serving bowls; top with crumbled bacon, and sprinkle with chopped parsley.