Fill your (clean) sink or large stock pot with warm water and a drop of produce wash. We love Biokleen Produce Wash
here - it may cost a few dollars more than expected but the bottle does last a long time.
Swish the vegetables around in the water a few times and allow dirt to fall to the bottom of the pan/sink.
You can see the dirt has fallen to the bottom in this spinach soak.
I usually de-vein, etc while in the water, then rinse as I pull them out of the water, then chop or otherwise prepare. It works quite well and I feel much better about the vegetables.