Soak the beans in cold water overnight. Drain and dump into a slow cooker. Add the oregano and chili powder and stir to mix.
In a separate pot, soak the ham hock for 2 hours. (You can also soak, refrigerated, overnight if you wish). Add to the slow cooker and add the liquid from soaking the ham. If the ham hock is not fully covered, add more water. Now add the onion and stir well.
Now make the house dressing by mixing together the garlic powder, salt and pepper. Use this seasoning to season the beans.
Cover the slow cooker and cook on high for about 5 hours or until beans are very tender.
Recipe by Hillbilly Housewife at http://www.hillbillyhousewife.com/slow-cooker-pinto-beans.htm