Hi, there. I study nutrition and physical training. A good way to clean non-organic produce is the vinegar solution you've mentioned, at least it's the most conventional and easiest means of doing so. A better way, however, is to use powdered activated charcoal. It is what is used it water filtration systems, and used for a variety of other things, because it absorbs toxins. You would fill your sink with water and add in your produce, plus two table spoons of activated charcoal powder. Leave it soak for 20 minutes, or longer if you like, then drain and rinse everything with clean water. The activated charcoal will absorb any pesticides, etc, on the produce.
Also, have you heard of the 'dirty dozen' produce? It's the produce that has the most exposure to chemicals, thus making it more important to buy them organic, or take extra precautions in cleansing them. The dirty dozen of fruits and veggies include: apples, strawberries, grapes, celery, peaches, spinach, bell peppers (all colors), nectarines, cucumbers, tomatoes, and potatoes. All of these things consistently have more contact with chemical pesticides and such. With that said, the list may change over time, so recheck periodically. I hope this helps! -Autumn