Bought house with very pungent urine odor in flooring....how to deodorize with bleach?

We ripped out the carpets (which were grossly smelly and stained), and soaked the floorboards with Nature's Miracle. The smell is still partly there, I have read on here that multiple mops with bleach works wonders. How much should I dilute the bleach? We are planning on applying kilz afterwards. Any other suggestions from experience would be appreciated! Thanks so much! :)