I am using a waste veg oil heater (chip pan oil) in my garage. It consists of 2 jam jars with a slit in the top and hessian sack as a wick, with two big terracotta plant pots stacked on top. it does the job, heat wise but i am getting about 2 handfuls of soot a week in the pots. It looks decent stuff and i would hate to waste it but the eye can be deceiving. Will this soot be any good in the compost and does it have any value?