So I tried putting one drop of tea tree oil in my neti pot last night for the first time, and again this morning. The effect so far in this short time has been very, very noticeable. Both my nostrils feel far more open than they have in months, since this sinus fiasco began. I spent the entire train ride to work this morning hoping that I wasn't jinxing myself by thinking about it too much, and that the tea tree oil might finally be the magic bullet I've been searching for to clear this junk out of my sinuses and ears once and for all.
Like you, I am also purging a lot of white foamy/doughy mucus in the mornings. This morning after the tea tree oil last night there was more of it than usual. Keeping my fingers crossed!