No, im referring to inserting a letter in the igros to her an answer on a question.
Also, does it have to be a רוחניות question or I can just ask any silly question, like which airline to fly?
ETA: don't get me wrong, I'm being serious. I want to experiment. Not trying to be disrespectful.
It's not a "trick" to experiment with. As many others have quoted, the idea is that you are writing to the Rebbe, seriously. How he answers, is up to him. It could be through a book of his letters or many other avenues. If it was 1987, and you heard miracle stories of the Lubavitcher Rebbe, would you write a letter to him as an "experiment?" If so, go ahead. If not, then don't do this either.
There are many stories of people who wrote letters but did not place it in the Rebbe's igros (they placed it in the Ohel, for instance), and then studied the igros only to find it directly answered them. The same is true for other parts of the Rebbe's Torah. And, as others have mentioned before, the same thing occurred when the Rebbe, and other Rabbeim, were alive and people "wrote letters" with thought, or wrote letters that did not actually get received by the Rebbe -they received answers. Sometimes written (as with R' Mendel Futerfas mentioned previously).