If you do your cleaning internally, either with a dedicated member of staff or using your other staff you are almost certainly wasting resources when you could outsource your cleaning functions as well as other janitorial and maintenance work to a maid service or similar.
If you are having cleaning done by your other staff you are going to be taking up time when they could be focusing on their core jobs that are what create value for your business, so don’t just think of the cost of the wages of those staff, who may well be paid more than the hourly rate for a maid service anyway, it is also costing you the value of the work they would produce.
If you have a dedicated cleaner you are also probably wasting money though, it may seem on the face of it that the hourly rate you pay a cleaner is less than you would pay a maid service but there are extra costs. For a start how about the extra payroll costs, you may be paying for various benefits that you give to all employees even if they work a few hours each week including holiday pay and sick pay.