If you have chronic sinus problems, go to an ENT and make sure you don't have polyps or something. Snot actually serves a purpose, so perpetually washing it away isn't necessarily a good thing. Filtered water isn't enough - either distilled water or tap water that has been boiled for (I think) at least a few minutes will help prevent infection (and I wouldn't use tap water period if I lived in the south...chances of infection are slim, but there are a few infections that have a high mortality rate). Proper cleaning of the pot or squeeze bottle is also important.
Rinsing your sinuses 3 times a day if you're not sick is excessive (a few times a week is fine). If you're using Afrin (not just regular saline) for more than a couple of days, you risk a physical dependency with an awful rebound, so don't do that.
If you go for the squeeze bottle (which I use), be careful when you squeeze. Squeezing too hard, or using it when your ears are clogged, can actually damage your ear drums.