They are great. I find it easier to use the regular saline sinus rinse from the bottle. It's amazing what comes out of there even when using it right after blowing your nose.
I have come across a lot of people at work and around town with bad sinus infections. My brother in law just had one so bad he ended up with not only sinus issues, but an ear infection and a fever. The anti-biotics should help, but rinsing your sinuses out twice a day should do wonders for you.
Hope it clears out for you soon.