SPG block post MVD

Has anyone tried a Sphenopalatine Ganglion block to treat the remainder of their pain after MVD?

How was it administered?
Did it work and how long did it remain effective?

I am scheduled to have one this week after having undergone MVD in December last year (diagnosis: type 1 and type 2 TN, geniculate and glossopharyngeal neuralgia).

Thanks!