Certified GKH Gardening Expert
Reducing compost time comes down to heat, and proper bacteria count. Although there is some overlap with the bacteria and fungi between the two... There are many in the septic solution that will not thrive or even survive in condition for soil, or compost.
It is best to use microbes that are meant for the garden to avoid waste. There are many on the market, and they are inexpensive. Many hydroponic stores will give free samples away as well.
This article will help you to compost properly: https://www.gardeningknowhow.com/composting/basics/ultimate-beginners-guide-composting.htm