Any person who meets the requirements of RCW 18.57.020 as now or hereafter amended and has been examined and licensed to practice osteopathic medicine and surgery by a state board of examiners of another state or the duly constituted authorities of another state authorized to issue licenses to practice osteopathic medicine and surgery upon examination, shall upon approval of the board be entitled to receive a license to practice osteopathic medicine and surgery in this state upon complying with administrative procedures, administrative requirements, and paying a fee determined as provided in RCW 43.70.250 and 43.70.280 and filing a copy of his or her license in such other state, duly certified by the authorities granting the license to be a full, true, and correct copy thereof, and certifying also that the standard of requirements adopted by such authorities as provided by the law of such state is substantially equal to that provided for by the provisions of this chapter: PROVIDED, That no license shall issue without examination to any person who has previously failed in an examination held in this state: PROVIDED, FURTHER, That all licenses herein mentioned may be revoked for unprofessional conduct, in the same manner and upon the same grounds as if issued under this chapter: PROVIDED, FURTHER, That no one shall be permitted to practice surgery under this chapter who has not a license to practice osteopathic medicine and surgery.