This freebie from 2010 has returned!
If you don't mind going on a little link hunt, you can get a free NeilMed Sinus Rinse bottle kit. Simply click through to where it asks for your name and pick “p1886b” from the dropdown list. After that, you'll be presented with 17 “slides,” which you don't have to read and can quickly skip through. You'll then be presented with a signup form and finally, a “quiz” where you have to get 18 out of 20 questions correct.
The quiz scores you in real time though! So you can click randomly until you get the correct answer. All in all it should only take a few minutes.
And if NeilMed isn't your allergy spray of choice, I was able to find this huge $2/1 XYZAL coupon.