I've always been pretty careful about washing veg, rice, and other things before using them. However, I never gave beans a second thought. Why? Because I soak them (for the most part) and then discard the soaking liquid. Until someone mentioned to me all the lovely places that beans sit around in before getting to you, and how most of those places are dirty or dusty. It's not a problem of the plant being unsanitary, but just a function of how beans get packaged and the rest. It's nobody's fault.
But it's plenty disgusting.
This morning, I was about to put a few cups of pinto beans to soak for a chili. I gave them a thorough rinse. I scooped out the beans, and found a layer of dirt along the bottom of the container I'd used to hold the beans while running them under water. I was absolutely disgusted. I gave the beans a few more rinses, and only put them to soak when the water ran clear.
I'd assume that this goes double for hulled or split daals, like urad daal, red lentils, chana daal, etc. I never gave it a second thought, but I think I will from now on. I really don't want that stuff in my food.