yes, it's actually alot easier than it sounds as long as you start with actual mushroom mycelium instead of spores. Where I was doing it in the southeast US, it rained alot and the humidity was constantly in the upper 80's so conditions were good from the start.
To successfully do it, I think there a couple things you should worry about. First off, dig a hole about 3" deep and fill it with either cow dung, worm castings, or any other nitrogen rich poo that you can find and wet it down. Then mix your mycelium throughout the dung making sure it is evenly spread among the pile. I only covered them up with about an inch of pine needles but you could case it with coco coir (coconut husk) and then spray it liberally once or twice a day to keep the humidity up. In about a weeks time, you will see fruits breaking through your casing layer or pine needles if conditions are maintained. That method has worked for me at 2 different residences by just using lots of water and providing them with a good source of dung. Don't worry about contaminating the spawn because nature will take care of it once it is outside and growing. Good luck
