Place roast in a slow cooker; sprinkle with seasonings. Cover and cook on high setting for 2 to 3 hours, until fork-tender.
Remove roast; cool. Reserve 1/2 cup cooking liquid. Grind meat with a meat grinder; add eggs and crushed crackers. Add reserved liquid and enough water to obtain consistency of thick soup.
Return meat mixture to slow cooker and cook on low setting for an additional 2 hours. Spoon onto warm buns.