Since you do not wish to use a drug based spray a Neti-pot is a good option. Unfortunately, the Neti-pot is not very convenient.
I have been suffering from Sinusitis for the last 15 years and have tried out many treatments. Based on your preferance for a nasal spray which offer quick relief, which is convenient to use and which is also drug free, I can suggest a nasal spray that I use regularly. It is called Sinox Spray.
Nasal sprays with chemicals and drugs stimulate the nose membranes to produce mucus. If used regularly, the body becomes tolerant to the nasal spray decongestant and the effects of the drugs. The patient ends up using more nasal spray to overcome stuffy nose and the body increases its effort to counter the effect of the nasal spray. This vicious cycle is called rebound congestion. The patient starts depending more and more on the nasal spray, not realizing that the nasal spray is actually fueling his/her dependence.
The spray that I use, "Sinox", is a hi-tech nasal spray which is non-systemic and drug-free. Since it is gentle and non-habit forming, it may work well for you; especially if you are concerned about the addictive or habit forming properties of regular nasal spray.
Sinox also has "prophylactic" uses similar to Airborne Health Formula. I spray it in my nose around the time of exposure to a lot of germs (airplane, train, subway, hospital). This helps in reducing the likelihood of me getting sick.
I hope this helps. Just wanted to share the experience I have gained fighting sinusitis for 15 years.