Question: how to do oju before namaz?
Answer: Start by making niyyah (intention) to perform wuḍūʾ and cleanse the self of impurities.
Recite bismillah.
Wash the right hand up to the wrist (and between the fingers) three times, then similarly for the left hand.
Next, rinse the mouth and spit out the water three times and rub the teeth with a miswak.