Six hours, 360 minutes or 21,600 seconds. No matter how you measure it, Americans spend a lot of time each week mopping, scrubbing, cleaning their homes, according to a new survey by the American Cleaning Institute. For some, all that time still isn't enough time as 28% of respondents spend more than seven hours on cleaning. Yet, roughly a third of Americans wonder if they should be cleaning more and if they're cleaning correctly in the first place!  Some of the ACI survey findings ...