The administrator of the division of occupational and professional licenses shall appoint such number of inspectors as may be required for the effective enforcement of this act. All inspectors shall be skilled in plumbing installations with not less than five (5) years actual experience, shall possess certificates of competency prior to appointment, and shall be fully familiar with the provisions of this act and rules made by both the administrator and the Idaho plumbing board. No inspector employed by the division of occupational and professional licenses and assigned to the enforcement of this act shall be engaged or financially interested in a plumbing business, trade, practice or work, or the sale of any supplies connected therewith, nor shall he act as an agent, directly or indirectly, for any person, firm, copartnership, association or corporation so engaged. Inspectors employed by municipalities electing to claim exemption under this act must possess the qualifications set forth in this section.