So now, when I buy my grapes, I take the few extra minutes before I put them away to get them all ready! I remove the grapes from the stems and place in a big colander in the sink.
After a good rinsing, I place 1 small drop of liquid dishsoap in one hand. I then rub my hands together to coat them, and then run my hands through the grapes to lightly wash them. If you've placed just a drop of soap on your hands, you won't even see any foam at this point. Just enough to break through that film on the grapes. Once I've done this, I rinse VERY WELL. Then I let drain for 5 minutes in the colander, and then place in a container for the fridge.
Now, when we want grapes, we can just grab what we want--they're clean, and they taste GREAT! Works for me! Check out other great suggestions and tips at http://rocksinmydryer.net