As speed decreases, maximum wheel braking is the thing which will help most. Whilst full flap might increase drag, the sudden lift increase could prove embarrassing!! I suggest that closing the throttle and braking as hard as you can without causing the tyres to skid would be your best course - once you have started the deceleration, carefully moving the control column back will help increase the 'weight' being carried by the braked wheels and hence the effective braking of the aircraft.