I know all the arguments against using crass clippings....importing grass seeds into your beds, too "hot" as it decomposes, makes a dense layer that doesn't let air and water pass through, etc.  BUT, I just can't use it all for compost, and I can't stand sending it to a landfill, either.   Anyway, I did it.  I've been using it for about a month now, and although not the most attractive mulch, it's doing the job.  I have about 1400 square feet of beds, so it'll be a good test.  About once a week I use a shrub rake to stir it up and break up the layers...very easy and quick.  It's decomposing well and the worms love it!  We'll see.

I agree with everyone else here that it really helps to dry the grass clipping before using them as mulch to prevent clumping.  I think you made a great choice by not sending the clippings to the landfill due to the fact that organic matter and the nutrients derived from it are being lost to the landfill.  An environmentally sound option is the direct return of fresh clippings to the lawn. There is an actual technique to this which is known as grasscycling or grass composting.  It is not only used to retain natural nutrients in your lawn but also your garden beds when used as a compost.