Sorry, when I posted the original post I guess I had assumed people always wash the outside of all fruits (and vegetables) before eating them. Fruits & vegetables go through ALOT before being purchased: a variety of bugs & possibly worms/rodents toilet, lay eggs/cocoon on them, they've probably fell or rolled on the filthy ground, kids snot on them and have possibly licked them, shoplifters may have had them "hidden" in their pants, many people whose hands have touched many things before touching the fruits/vegetables have touched them/sniffed/ or sneezed on them...someone may have had them in their cart with their chicken or hamburger leaking blood on top of them strolling around the store for over an hour and then when they get to the checkout, they decided they don't want the fruit anymore so it goes right back on the shelf to wait for YOU. A clerk may have not had a convenient place to put the returned fruit/veggies so they threw them in a dirty trash can only to dig them out a few hours later to return them to the store shelf. (I've seen it all happen!)
Washing a lemon (or any fruit/vegetable) with a peel isn't going to remove any pesticides that have leeched into the peel. Many doctors still say that consuming the peel has more health benefits than avoiding it. (I've been reading a whole variety of medical/health and wholesome food/cooking & nutrition books, magazines, journals & newsletters for years. It's ironic how people can get so paranoid about pesticides in fruit & vegetable peelings but have no problem with the chemicals they inhale in their cigarettes, the chemicals that affect their BRAIN that they consume in their alcohol, the chemicals/preservatives/unhealthy fats and sugars they gobble up in their junk food, the crap everyone is breathing in the air and drinking in their water. However, if the thought of pesticides in fruit & vegetable peelings is still too horrible to bear, there is always organic...and organic doesn't mean "100% pesticide-free" it simply means it's supposed to contain FEWER/lesser amount of pesticide than un-organic.
The best way I've found for washing fruits & vegetables (again, this only washes them---it doesn't remove leeched pesticides) is to fill the kitchen sink with water and add a 1/2 cup (for a full sink or 1/4 cup for a halfway sink depending on amount of fruit/veggies you're washing) with distilled white vinegar. I let them soak 20-30 minutes. Then do a quick rinse and pat dry. This kills 98% bacteria, eliminates risk of salmonella, and makes things like strawberries & blueberries stay fresher longer. It removes waxy coating. I know there are other things like baking soda, peroxide, etc that can be used for washing fruits & veggies but I like the vinegar the best...it just seems to leave everything more "fresh".