Somewhere between sober contemplations and inebriated thoughts, Lenz had cleared his soul of past regrets, uncertainties, and other things staining it.
He also is implying he cleaned his soul of the sin of drinking, before becoming “hollow”.
Also, Bleach is the name of an anime where Hollows are the souls of humans that fall into despair and negativity thus turning into monsters. He prevented this from happening to himself.