Ah. The hazard of editing a post. My comment is singularly focused on the dirty bath water. The ham hock looks wonderful and delicious.
When I use any dried beans, I pour the dry bean into my hand slowly, and pick out the bean-sized clumps of field dirt that often accompany them. I would guess that if you used a meter of some kind to measure the available N : P : K of that rinse water, it would not be impressive.
When will the ham hock and beans be ready to serve?
Bob
EDIT: if I type the N P K as I normally would, it looks like this: N
:K