The director of administrative services may establish, by rule adopted under Chapter 119 of the Revised Code, an experimental program to be implemented on a limited basis only which grants to employees in the service of the state vacation leave, sick leave, disability leave, personal leave, life insurance, or medical insurance benefits that differ from these benefits as granted by sections 124.13, 124.134, 124.382, 124.385, 124.386, 124.81, and 124.82 of the Revised Code. However, this program shall not reduce the number of hours of vacation leave, sick leave, or personal leave which an employee has accrued as of the effective date of the rule.