Couldnt you mix your soil with ready compost, personally im gonna mix it w/ food product compost, all fruits/veg. tea bags n shit. Then add some benefitial bacteria, and it should be some dank soil. You would just need to steralize the soil in the composting process, it can get +160' F when conditions are met. small/medium piles are the best but you can sucessfully do it with bins. When composting, what's inside your bin will determine what temp. it will decompose at (the rate of decomposition). And they make inside composters/bin's for if your winters are cold. Worm compost is good..well its fukin awesome, but its not sustainable thro out the year if your winter's are snowy. But the worms leave alot of little worms for the following spring, so thats an option if you have the space for a worm bin, they're easy to make. Either way, worm or reg. composting i bet would recycle your soil effectively