Let me be the first to congratulate you on being proactive.  Don't worry about us "not understanding", we have all "been there, done that, tried this or that, and really hate the ugly t-shirt it gives us."  Everyone else doesn't understand what us supporters see on a daily basis.  As long as you are there, gaining knowledge for him, and just letting him know that you are willing to work through anything...that is the best thing ANY of us can do.

As for your questions: Look for the Oxygen tab on the left side of the page.  It is the go-to abortive for CH's.  It doesn't work in 100% of the cases, but at least try it out again, following what the tab says. But basically it will work when used at flow rates of at LEAST 15 lpm and with the use of a non-rebreather mask.  The other masks available seem to have no effect on aborting a CH hit.

As for the vitamin regime, it has proved to be another one of those go-to long term tries at becoming PF.  I believe it is right up there on the number of CH sufferers who find relief from it.  Again, with any medication, it may not work for some like it has for others.  I will echo something Batch says about it, your husband needs to go get his 25 (OH)D blood serum levels checked. We are finding out that a majority of CH sufferers are severely deficient in this key vitamin.  There is a thread started in the Medication area entitled "123 Days PF and I think I know why" that lays out exactly what is needed. The blood test will give him and you a rough idea on how long it will take to become PF.  Average response times vary, but could be anywhere from a few days to a week or two.  Added bonus is that all the vitamins  are over the counter and cheap (well, in comparison to some of the medications.  Additionally, if it does not allow him to go PF, it will greatly increase his overall well being.

As for the taurine, again, it's another "at home" remedy that has seen several hits aborted when taken right at the onset of a hit.  Red Bull energy drinks, or some other brand that has about the same levels of taurine can abort the low level hits. 

And don't worry, really...this is a place for us Supporters to vent our frustrations, our fears, our worries to other people who understand EXACTLY what you are going through.  Keep us updated and let us know what is going on.