Start with mild solution, and adjust to what you can tolerate.
Over the sink with mouth open, and one nostril closed, insert tip of "hydro Flow" machine in other nostril. Turn machine on and let solution flow in the nostril, and out your mouth. Repeat for other nostril.
The idea is to get the solution in all sinus cavities, and not just wet the nasal passage. Expell, and repeat until all solution is gone.
Ocassionally you can wait a while a repeat the whole process to see if you dislodged anything that didn't exit the first time. I have had that happen on several occasions.
Re: 35% H202. Handle carefully as it is a potent oxidiser. Keep away from the kids.
Dilute 11 oz of distilled water to 1 oz of 35% H202. Store remaining 35% in black trash bag and put in freezer. Will not freeze, but will stifle loss of potency.