I couldn't find the article about letter destruction but I did find this about the use of lettering in dadaism. I think this should point you in the right direction. http://www.artmargins.com/index.php/2-articles/179-foksal-gallery-1966-72-between-place-and-archiveThe article I read was printed in the early 1900s and was specifically about how dadaism and the destruction of lettering. I remembered the article because it reminded me of ramellzee's belief that writers were arming letters for war by using arrows to defend itself, the letters, from attack.
It was probably a Voltaire letter or interview. Although it also could have been a Satie, or Breton publication. They should keep you busy for a while.
Thanks Sizer, Im looking forward to finding some time and reading it.