Okay, so I have injected mushroom spores in vermiculite brown rice flower, and a bit of perlite and there in my closet is there anything I should do besides leav them there?
If you want a specific answer, you need to ask specific questions... How much does something extremely light weigh? What are the dimensions of a small scale application? How much is the smallest space possible? If you can't afford aerogels, how much can you afford? How much heat are you worried about? What is the highest temperature the insulation will see?
Plastic foam if the heat isn't too extreme.
try vermiculite from pet shops its a very lite mineral composed mainly of trapped air
