I should have said, "I can get away with just rinsing them". That might have been clearer.
I've only tried making bean soup, split pea soup, and refried beans in the crock pot.
The one time I made bean soup and left the crock pot on low (even for 8 hours), the beans were still hard.
With split pea soup and refried beans, the recipes said to put them on high for 8 hours (even though I normally cook on low in a crock pot), and I've never had any problem with the peas or the beans being hard.
On high, it take my crock pot about 3 to 4 hours to start the water boiling and then I just let the water (actually chicken broth) boil for another couple of hours. With the pinto beans, it's to turn them that pretty dark brown color so I can mash them into refried beans.
And yes, that's how I make my refried beans (with spices, of course), even though it's not the traditional way. So much cheaper and better tasting than what I get in a can.