Whilst it might be a seemingly obvious observation, I have just found that the correct temperature of water and the correct concentration of salt and bicarbonate of soda is crucial to the success of irrigation.
I have been rather lax in my approach in the past (with regards to the mixture) but after getting a bit more serious about this I have noticed an improvement.
I now only use boiled water and I clean my neti pot and Neilmed bottle properly. I'm using the pre-mixed sachets at the moment but either way I thought I would share this with everyone.
For the last five days I have been using the Grossan Hydra Pulse. A lot of other reviews sing its praises, but for me it's too early to tell although it is fairly safe to say it appears to rinse deeper than the other methods.
I still observe that water temperature is very important and I have on occasion 'got it wrong' which leads to several hours, if not the full day, with inflammation.
Agree that water temperature and salinity play important roles. Haven't heard of the Grossan, I'm trying out Sinox myself. So far I find that Sinox works much better than handmade saline solution, or the Neilmed sachets. The Sinox ingredients include far more technically-specified salts and carbonates, which seems to help a lot with keeping the sinuses clean throughout the day. I actually find that I'm consistently blown away by how well it works, even (or especially) compared to the other methods I've tried. I used to think those other methods were working great, but now I find the Sinox helps so much more immensely.