A glass of water does nicely, so does a slice or too of fresh bread. Suggested cold thing 1. A spoon dipped in cold water. If however it spreads too much, the problem may be that the cookie sheet is too warm. Or wrap the whole works in a towel as it comes hot from the oven and let stand for 5 minutes.
Some times greasing the spatula helps.
Or juggle a handful of ice cubes or as long as you can bear, the dough will not stick to them. Any corn that has been thoughtfully prehusked for you by your well-meaning supermarket probably fits into this category. Before you cook it, slice a small piece of, and stand the ears on end in an inch of water for a half hour or so. A tablespoon or 2 of corn syrup will have the same beneficial effect. For stubborn silks, a damp paper towel or even a whisk broom may be used.