Nice! Pleurotus is so hard core that you probably don't need to sterilize.
Even if it does get contaminated, you'll have experience with the strategy for when you do use a pressure cooker.
If you don't have one yet, "All American" is the best brand to get (it doesn't use a gasket). They're spendy, unless you can find one at an estate sale, or somewhere similar. Next in line is "Presto" brand. I'd only consider other brands if I was desperate.