I think it works pretty well. I don't have the neti pot but just the squeeze bottle from the same company. I got a sample of it from my allergy doctor and it worked pretty well, then I noticed Walmart carried the bottle + 50 packets for $15, 100 packets for $13, or the neti pot. So I just got the 100 packet refill. I don't need to use it very often, but its great when I get very congested.
I had bought some nasal drops, now have the same type of stuff as a spray (its just pseudoephedrine really), and it works kick ass in 5-15 minutes for clearing up even the most clogged of noses. But, I normally do it once at night, except when I wake up during the night or the next morning, my nose is clogged completely, even worse than before using it the night before (it that is possible). And it's weird, cause I only had used the stuff once the previous night, and I generally only use it once per day for 1-2 days every few weeks, at most. So I am nowhere near getting dependent on it or using it more than it says (not even close really), but even after just one use, it seems that 8 hours later and my stuff is effed up.
So I've kind of avoided using it lately after the past few times of having it get so much worse a while after using it once. I haven't had really any problems anyway, but if I do, I'll stick to the nasal rinse. I also have some generic saline spray, but it doesn't really tear through heavy congestion like the medicated saline spray.
As Eli said, the neti pot still doesn't work as well as the medicated spray. But you know yourself that you can't keep using it like that. So I'd suggest using the neti pot when you aren't completely clogged and you should get some results with a few days of use.
It looks kind of ridiculous to use, but ahha I think it is kind of funny anyway (the picture of the woman bending down to use it, hah) and who cares really if it works!