I like to keep it simple when charging it. I just add amendment mix, a little water, and stir. Come back the next day and stir again. If it still smells like char I add more mix with a little water (making sure not to water log it), stir and let it sit.
I thought initially I could get away with just adding worm extract, but without the stirring every day or two it will go anaerobic then it's ruined.