Do you remember a few years ago there was a big push by Proctor & Gamble for their new product, FIT? It was an all natural fruit and veggie wash that would clean all of the dirt and pesticides away. Problem with it was that the price got to be a bit high if you used it as advised. I have been using a version of it using my own ingredients that is by far cheaper. When I wash a piece of fruit or veggie (apple, pear, tomatoes, etc.) I pour a small handfull of baking soda in my palm, add a few drops of water to make a paste and rub this into the skin of the food to be washed. Rub thoroughly for a minute and rince off with clean water. Done! A one pound box of baking soda costs about 50 cents (2# box for $1 at Walmart).
When washing grapes, I add an extra step. I fill a large bowl with clean water. Add about 1/2 cup to a full cup of white vinegar. Add grapes to bowl, THEN add about 1/2 cup of baking soda. Of course this reaction creates a fizzy mess (so do it in the sink) and you should agitate the grapes in this mixture to get a really good cleansing of the grapes. The reaction seems to wash away all of the residues and dirt.
So how clean does this really get the food? I have no scientific basis to go on. I can tell you I stopped eating pears and apples because when I did, my lips and mouth would start to burn and I would get an itchy, burning sensation in the back of my throat. I believe this was from the chemicals sprayed on the food because I ever had this problem when I was a kid. When I did this recently on a pear, I was surprised that I was able to eat the whole pear, skin and all. When you wash the grapes and taste the for the first time, you may be surprised how smooth the skin of a grape is. Those are my observations. Try for yourself and let me know if you think they work or not.