Fortunately my sinuses have been good lately but a year ago I got a kit from my drug store which contained a plastic bottle rather than a motorized pump. It said boil the water, let the water cool down and add a packet of something that I cannot remember what it contained. Probably salt. By squirting the plastic bottle in one nostril the water exits the other nostril. I used boiled tap water but would understand that distilled water could be used. I use distilled water in my CPAP machine though.
Anyway the effect of water sluicing through the nostrils feels weird. I felt that it gave some relief from sinus problems though. I followed the instructions closely.
Cheers, Guy.