The only way to effect the nitzutz of Ra is unintentionally. It is for this reason that on Purim one must reach ad dlo yada – from Pri Eitz Chaim.
“This that our rabbis of blessed memory said ‘a person must drink on Purim until the point that he does not know the difference between cursed be Haman and blessed be Mordechai,’ is for the following reason:
There is a spark of holiness in all of the kelipot which enlivens it; were this spark to leave it, it would immediately completely cease to be.
On this great day that there is a great illumination we want this spark as well to receive vitality from this revelation; we however don’t wish for the kelipot themselves to be illuminated.
We therefore must say ‘blessed be Haman’ to draw down this light to this spark.
It must however be said unintentionally after one is already drunk and out of his mind, for, if it were said with intent, it would G-d forbid give light to the kelipot as well.”
(Pri Eitz Chaim, Sharei Purim, Ch. 6)