By that you mean, lay them on a cookie sheet uncovered and put in the freezer? We did that once with kale. Just froze the leaves for an hour then bagged them up. That worked pretty well. I just never did that with anything else.I don't go through celery often enough to make planting it worthwhile. So, like you are planning, washed and into quart sized bags they go. For my peppers, I flash freeze them first. Never have done that with celery