Hi Begginer,
I googled a little and have found some good advices:

You shouldnt use any growth suppliments, which is also stipulated in the user manual which you will receive with your extender!!!

Put some cotton between your head and the cushioning device, as sometimes it can get irritated and rub against the skin! Which gets bery painful, and you will have to give it a couple of weeks to heal, as it can tear the skin...

And then, you will be annoyed as you want to use to device as much as possible to get the desired effect. Good luck!