Generally, this is good advice.
But a little care would ensure that you dun get clogged nozzles even if you use 3rd party ink. For example, just turn your printer on every 2 weeks or so. When my Canon printer is turned on, it seems to do a bit of a nozzle flushing. After a few more minutes of inactivity, it turns itself off. So this little act by turning it on once every 2 weeks or so, the heads remain free from clogging. I believe Epson also does this. Not sure about HP/lexmark though.
Yes, you waste some ink, but the ink so very cheap compared to the original. I've found that colors I'm getting from my Sepoms ink is as good as the original Canon in terms of color. As for longevity, I dun know yet as the prints I've made are still too new.