The conventional method for deleting a post on TFL seems to be to cut all of the text, replacing it with "deleted." But you can't make the whole post disappear, as far as I can tell.
The evidence of your presence will linger....
"Once the writer in every individual comes to life (and that time is not far off), we are in for an age of universal deafness and lack of understanding."
(Milan Kundera, Book of Laughter and Forgetting, 1980)