Buy it?
Composting takes time as it's the heat and the microherd that breaks things down. They work fast but they are small
There are a lot of organic ones that you bubble from 24 - 48 hours that are cheap and easy.
Alfalfa
Molassas
epsom salts
eggshells ground in the coffee grinder
Mike's hard lemonade*
There are probably a lot more should you do a google search on the subject.
*That's for me