Our 733 QRH doesn't recommend opening the window for smoke removal in 'normal' configurations, after a number of items intended to increase ventilation using packs and pressurization valves it states
CAUTION: Do not open any flight deck window. Keep the flight deck door closed.
Further down there is an entry for the case when "the packs are off and the smoke or fumes source is confirmed to be on the flight deck:"
CAUTION: Window should not be opened unless the source is confirmed to be on the flight deck.
Normal holding airspeed - Establish
First Officer's Sliding Window - Open
Return to SMOKE, FIRE OR FUMES checklist and do the remaining steps.