Hi there!
After some substantial smoking of the N. Rustica plant i have focused in on what i consider the best part of the plant - The flowers. It produces a very gentle flowery taste with a small element of tobacco aroma.
If you feel the need to create a smoke deluxe model you wanna make sure to only get the yellow part of the flower.
I have cured them in the oven at approximately 80 degrees for 30-50 minutes with good results, as the leaves of the flowers are thin they dry out quickly.
As i searched on the internet about some ethnobotany regarding the flower usage of N. Rustica the information was vague, a uncertain source claimed "Natives" would consider the flowers to produce the best smoke, if someone knows more about that topic it would be fun to know.
Be well and happy toking!