(2) To restore the dwelling unit to its condition at the commencement of the tenancy, ordinary wear and tear excepted; provided, however, that this subdivision does not preclude a landlord and tenant from agreeing, in the rental agreement between them, upon amounts or fees to be charged for cleaning of the carpet, and such amounts actually expended for carpet cleaning can be withheld from the security deposit, so long as the rental agreement also includes a provision notifying the tenant that he or she may be liable for actual costs for carpet cleaning that exceed ordinary wear and tear, which may also be withheld from the security deposit. Within thirty days of the end of the tenancy, the landlord shall provide the tenant a receipt for the actual carpet cleaning costs; or