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It's really hard to estimate that accurately, because for me something like 90% of cleanliness is developing habits that couple it with the tasks that necessitate it: always and automatically washing dishes after cooking, putting away used clothes and other sources of clutter, etc. Habits don't take mental effort, but for the same reason it's almost impossible to quantify the time or physical effort that goes into them, at least if you don't have someone standing over you with a stopwatch.
For periodic rather than habitual tasks, though, I spend maybe half an hour a week on laundry (this would take longer if I didn't have a washer and dryer in my house, though, and there are opportunity costs involved), and another half hour to an hour on things like vacuuming, mopping, and cleaning porcelain and such.