Question
Ronald:
My grass had grown tall for lack of mowing. So, I bagged the clippings and dumped them in my back yard. Now they are decomposing and smell awful. Is there a technique for getting rid of the smell easily. I know that I can "turn" the pile periodically, but it is a lot of grass and lots of work. Is there an enzyme or additive that can be purchased that will accellerate the process, or eliminate the smell.

Answer
"Smell" is a very subjective thing. What you might call an "awful smell" in a compost pile, I might find as quite normal and indeed, that smell might indicate to me that the composting process is going well.
Composting is an aerobic process. That is the main reason for turning a compost pile inside out every so often. In the absence of air (anaerobic ), fermentation takes place.
I suspect that the clippings are fermenting; and I do not know of an easy or short-cut method of aerating the pile.
If you do decide to 'bite the bullet', I suggest that you read up a little bit on aerobic/anaerobic composting Click Here for some information.