Remove any fat on the roast. Tenderize roast using fork - stab repeatedly covering the entire roast. Rub oil into roast and LIGHTLY sprinkle garlic and onion powder over oil. Rub in.
Place the roast into a crock pot. Stir water, broth and au jus mix together; pour over roast. Cover and cook on low for 5 hours.
Remove roast from crock pot. Shred roast; return to crock pot. Cook roast for 1/2 hour on high.
While roast simmers, open hoagie rolls. Butter each side and place on baking sheet, butter side up. Broil for 3 minutes until toasted. Watch for burning!
Place beef on toasted bread. Add a slice of Swiss cheese, if using (toast in toaster oven or low temperature oven). Serve with broth from the crock-pot.