This topic is a "your mileage may vary" scenario. Personally, THC doesn't have any positive effect for my fluency. I have access to a medical dispensary and have tried indicas, sativas, hybrids and edibles. I find that I just get trapped in my thoughts as well as becoming increasingly self conscious about my fluency. It really depends how you respond to thc as well as whether anxiety is a problem or not. If it does work for you, that's awesome!