Prior to the adoption, amendment, or repeal of any rule, the commission shall afford reasonable opportunity to interested persons to submit data, views, or arguments, orally or in writing. The commission or its staff, in its discretion, may use informal conferences and consultations as a means of obtaining the viewpoints and advice of interested persons, and it may appoint committees of interested persons or experts to advise it with respect to contemplated rulemaking. The powers of such committees shall be advisory only. In no event shall the commission take any action except in accordance with the law.