Here's what I do with mine.....

Even the new ones......I open them up and deploy the blades to make sure they're working smoothly. I then lay them on a piece of newspaper in my shed and pray them with a light coat of WD40. I work that into the mechanisms.....then let them lay to dry. When they're "dry"......I work them a little more.....then spray them with e3. I spray them a time or two more and the smell of the WD40 is gone.

I also have begun (at Rick James recommendation) to use the small rubber bands almost at the end of the front of the blades.

Even without doing this....I have never had one open in flight.....and I've never had one NOT open.

Good luck whichever head you choose.