Just my experiences which hope will help:
Sinus probs in the descent (both commercial and private!) ARE that painful -I thought my left eyebrow was going to explode!! I've found that if I am flying myself, as long as I don't descend at more than 500'/min, I'm OK. Try telling the skipper THAT on a commercial flight though!!
However, without resorting to drugs I found that a good blast or ten of Vicks Sinex keeps the toobs clear for descent.
Hot water in an inhaler with a few drops of 'Karvol' also works well.
The one time used Sudofed, it merely kept the prob at bay and prevented pain! What I really needed was anti-biotics as it was an infection.
Not nice -wouldn't wish this on anyone!