Ball Covered in Grass Clippings

With the rain recently I have had a couple of occasions where my ball is covered in crass clippings on the fairway. We are no longer on preferred lies so unable to lift clean and place.

I guess the grass clippings are classed as loose impediments, but there is a chance you ball could be sat on a lump of grass clippings, this is clearly frustrating when you have found the short stuff but are you allowed to clean / remove the grass from the ball?