I agree with everyone, especially Benny about using a cake pan or some kind of pan or box to catch the scrapings from the ceiling before they hit the floor. It makes clean up so much easier and you aren't walking around in the stuff on the floor which can be slippery and you will track it everywhere you go in the house.
I've see on one TV show where they had a scraper on a long pole (not sure if this was a tool you could buy). That would save a lot of Up & Down trips on a ladder One person scraped while another caught the scapings in a cardboard box. That looked like the best technique I have ever seen someone use.
To avoid gouging the ceiling with your scraper blade, you can round the corners off with a file. Even if you do gouge a little, you can easily fix it with a little spackle or drywall mud.
I don't envy you, so good luck :boohoo:
...Rich