Except as provided by chapter
42.52 RCW, no member of the board and no employee of the board shall have any interest, directly or indirectly, in the manufacture of liquor or in any liquor sold under this title, or derive any profit or remuneration from the sale of liquor, other than the salary or wages payable to him or her in respect of his or her office or position, and shall receive no gratuity from any person in connection with such business.