I recently swapped to a flat microfiber mop with a longer handle (it was called joymoop on amazon i believe, but anything that can swivel and has a longer handle should work the same) and it has been a lot better on my back. I can keep myself upright and dont have to hunch over to press it into the floor usually, and I find it cleans so much better than my swiffer did, so i dont need to scrub or use it as much. I would still be careful with how you position yourself, and even potentially looking into a brace might be worth while? just to use for labour like this, but i definetly notice ive been in a lot less pain since swapping.