...see the attached Kip scale...a beloved fellow clusterheads interpretation. it doesn't fit mine, but bear in mind the typical pain scale you'll get at the doc shop doesn't represent us either. it's importance is as a reference...kind of an "in reference" that clusterheads of an era used (use) to talk to each other in the same language....
The Kip Scale (clusterheadaches.com)
....there's really no way for us to gauge how O2 is going to work for you....timing/flowrate/breathing techniques/etc....took me hours of sometimes bitter experience to figure what works for me.....then it changes and ya start learning all over again....
....a few basics: get yourself a non rebreather mask (no holes/bag attached, see ClusterO2 Kit - Clusterheadaches.com - Online Store ) so you are getting 100% O2, start out with higher lpm flows (15-25+) and work your way down til ya find the sweet spot, if any. try various breathing techs like hyperventilation (most popular), slow breathing, breath and hold, a combo. most find it important if not critical to start at the first sign of a hit. many, like me, are benefitted by same time quick downing of an energy drink (min 120 mg caffeine/1500 mg taurine).....and staying on O2 for 5-10 mins after a hit aborted. since you are unsure when to start, you are just gonna have to try.... and record/remember your results. in my case, i put a time limit of 20 mins on any attempt because by then i knew it wasn't gonna work....and no sense wasting O2. in reality, i would probably stop sooner because i just "knew" ...and cannot explain how...you'll know......