Has anyone tried using Ebony Blades for Dark Brotherhood Contracts?

I just got this for my fourth runthrough and I don't feel like killing anyone that I know with it.

If I was to use it on DB targets, will the blade still upgrade?

Just tested this myself, and I can confirm it does work. I'm not exactly sure who upgrade and who doesn't, but using it on Nazir's contracts seems to up upgrade the blade.

http://www.uesp.net/wiki/Skyrim:Ebony_Blade