Washing Vegetables With And Storing Lemon Essential Oil?
I don't see a point to doing this at all. The lemon oil may act as a mild surfactant in larger quantity. Use water and elbow-grease to clean your veggies -- you're primarily trying to remove dirt. Use of Scotch Brite-style scrubbing pads (so long as they're detergent-free) works nicely for heartier veggies like carrots and potatoes, and a vegetable brush or cloth for more delicate things.

If you're trying to kill germs, you may want to try soaking briefly in a VERY mild bleach solution. If you're trying to prevent browning via oxidation, particularly in cut vegetables, acidulated water should do the trick -- add some lemon juice or crushed vitamin C tablets to water and soak until needed.