Cleanse is a special weapon skill that removes all ill-effects from the pirate using it. When activated, this blessing removes all negative status effects like Wounded, Stun, Poison, Grave Shackles, etc. Cleanse charges over time when the weapon is equipped.
It takes 30 seconds to charge and re-charge this skill.
There appears to be a Cleanse glitch. If you have a weapon with Cleanse, wait a few seconds, then press 9 and your character will use Cleanse. After this, you can trash the Cleanse weapon and you will still be able to do Cleanse!