You can find orange blossome water and rose water as well as other items at 3 places I know of in No. VA:
1) Mediterranean Bakery in Alexandria in the same complex as the Home Depot over, I think, in Del Mar.
2) Al Nakheel in Vienna in the Jade shopping center on Maple Ave. near the Amphora diner
3) Ali Baba bakery on Mill Street in Vienna
I'm Lebanese so I'm pretty familiar with the various suppliers in the area.
Chris in Vienna