Members and employees shall not participate, while on Board-owned or leased property or while on duty for the Board, in any gambling activity, including the operation of a gambling device, conducting a lottery or pool, a game for money or property, or in selling or purchasing a numbers slip or ticket. However, this section does not preclude activities regarding solicitations conducted by an employee recreation and welfare organization among its members, for organizational support, or for benefit or welfare funds for its members, these activities having been approved under section 3 of Executive Order 10927, dated March 18, 1961.