Thanks for the feedback. I hope that the sinus flooding helps you.
Just a warning though. With the back of the head down, and the nostrils facing up, the opening to the Eustachian Tubes is much more at risk of getting some of the liquid in it.
That is why I put the top of my forehead down. In that position, it is much harder to get liquid into the opening to the Eustachian Tubes.
The opening to the Eustachian Tubes is at the back of the throat. If the nasal areas are flooded and the back of the throat is down, and the face is up, then the openings could be "under water". To me, the only safe position to do a flooding, or any sinus irrigation, is with the face down, OR the top of the forehead down.
I have also done the flooding several times with my forehead bent down over the sink, and I have had no problems with my Eustachian Tubes getting liquid into them.
You might have been lucky, and not have gotten liquid in your Eustachian Tubes because you are not using much liquid, but, the only safe position to do a flooding, for me, is with the top of my forehead facing down.
I hope that you are able to get control over your sinus infections, like I did!