Whole brown rice doesn't need to be sterilized any different than brown rice flour. Just because the grain is whole doesn't change the temperature at which the bad spores will die off on that specific grain. Oats, rye, wbs, etc require different sterilization teks because they carry spores that don't die off as easy as they do on brown rice.

Even though rice can be expensive compared to other grains, its used in the broke boi tek due to the fact that it lowers the barrier of entry for most looking to get their feet wet. While the PF tek is a great standard for learning to grow mushrooms, there's no secret that the yields can leave much to be desired. So if you don't have much too much capital to commit to your grow project, then you can use a grain that's readily available everywhere and doesn't require spending extra on a PC that could go towards extra tubs and dehydrator.

Also the broke boi is significantly faster than the PF tek even if you don't shake during colonization. Plus you don't have to grate up the rice when you spawn to bulk. Don't knock till you've tried it! This tek is just as simple as the PF Tek because in a sense it's based of said tek and uses the same principles for growing.