I find your Renko work interesting, but I don't know that any one system is foolproof. In fact, we all know otherwise. Like other TA indicators, it takes some additional indicators along with some personal skill/experience.
I think that the Renko work you are doing has some great potential for longer term investing. You won't catch the bottom or top as quickly, but you will stay with the trend.
Unfortunately, the July "bottom" turned out to be just a pit stop. I certainly expected more of a bounce, albeit in a downtrend.
Keep up the good work!