If you figured out to do nitrogen correctly, I would say that is one of the easy and relatively reliable methods. Improvising a method is better than trying a completely new method in my opinion. Nitrogen is one of the painless and reliable method when done correctly.
How long was it before you were found? If it was more than 15 minutes, you probably were not doing it correctly.
I do want to add, my belief is first try to find sunny days, and then try to get rid of the clouds and if for unsurmountable reasons you are still not getting sunshine then choose a damn reliable method that can make your situation better and no worse. Sorry for being preachy. Just something I want to say (more for myself than anything else I guess).