I think 95% of this is governed by where you live, and the relative humidity there. I live in the desert Southwest, and NEVER drain my compressor tank, EVER. But the relative humidity is well under 20% most of the time, and can be as low as single digits. So there is no need. The air going into it is bone dry.
I noticed the OP is from Houston, one of the most humid cities in the nation. I don't think you can drain it enough under those conditions. And if possible, look into some type of dryer.