How to boil pork knuckle?
When I was a child every christmas day we would have ragout des pattes de cochon (pigs feet stew) With meatballs in it. It is definetly possible to cook pigs feet in a pot!

That being said, I have never done it myself. This looks like a good recipe, you can get a good idea of what to do.

http://www.food.com/recipe/rago-t-de-pattes-de-cochon-pork-stew-with-meatballs-398226