Neti Pot or Sinurinse will remove a lot of the remaining mucus. I deal with sinus infection year round, getting ~6-10 a year, and the sinus rinse has helped a lot in preventing and treating. You are lucky that you know what is causing yours, no one can figure out what is happening with me. I am only allergic to Mountain cedar and that comes to Dallas in the winter only.
My ENTs (yes, multiple, I have been to 4 and have had surgery once) are split over whether the sinurinse works better than the neti, but I personally use both. If the mucus is high up in my sinuses, I will use the Sinurinse. If it is lower, I will use the neti. The trick with the neti is that you can't just pour in one nostril and out the other. You must pour in one nostril, close the other, and snort the water in your nose and out your mouth.
It sounds awful and disgusting and takes some practice, but it works great, especially when you are dealing with a lot of drainage. The fist time you do it with an infection, you will be grossed out by the amount of green muscus you are spitting out.
Also, if you are using the Neilmed packets, get the hypertonic packets or double up the normal packets per 8oz.
Good luck, sinus problems suck.