It takes two cleans to turn over our 1400 and change 2 bed 2 bath cottage with COVID. The cleaners go first for about 2-3 hours (more time if extra laundry or dishes needs to happen) and we go after to re-disinfect, re-dust and put the finishing touches on the place for the next arrival-- wine in the fridge, welcome note and little chalkboard with their name on it, pillows placed the right way etc. It takes us another 1-1.5 hours. So I would probably double that for a house twice the size or triple for three times. We are very diligent about our cleaning though. Some might say OCD. We got dinged a few times early on by very picky guests so now we try our best to be picky proof.
We always say if we do another Airbnb it will never be bigger than the one we have now. Too much of a chance for parties and too much to clean and launder.