The friendly Dips spawned by Dirty Mind will be Isaac's main method of attack. It's a good idea to destroy as much poop as possible to build up a swarm, though be mindful of the limit on the Dips' number. Once the old ones start popping, save the poop for later.
Due to the Oh Crap transformation and E. Coli, enemies can simply be walked into to convert them into poop, which is immediately destroyed to heal back the contact damage and generate more Dips. This strategy will result in half a heart of damage against champion enemies, however.