Shell – Gnome 3: how to get a terminal with transparent background

I would like to make the background of Gnome Terminal
transparent. I know this feature has been removed from Gnome but
I find it very helpful. I am wondering what's the best way to
achieve this. I'm working under Debian Testing with Gnome
3 (Gnome shell 3.14.2) on a Lenovo Thinkpad X1 Carbon (3rd gen.)

I thought the Gnome extension "Transparent Windows" would be
good, but Google Chrome gives me "We cannot detect a running copy
of GNOME on this system…". This is a known bug. With
Iceweasel (Firefox), I could not find the extension under
extensions.gnome.org, but when searching for it via Google, it
showed up. I then installed it but nothing happened thereafter,
the extension does not show up in Tweak Tool -> Extensions for
example… (not even after reboot…). So I guess this is not working.

I then found devilspie (see https://rgrunber.wordpress.com/2013/11/12/get-to-know-a-command-devilspie/; there is also http://forums.fedoraforum.org/showthread.php?t=293843)
and did the following:

sudo apt-get install devilspie
cd ~/.config
mkdir .devilspie
cd .devilspie
emacs terminal-opacity.ds 
# put in terminal-opacity.ds:
(if
   (matches (window_name) "Terminal")
   (opacity 84)
)

One then has to execute devilspie -a
/home/myuser/.config/.devilspie/terminal.opacity.ds on login, not sure if I do this step correctly (any suggestions). For now I execute it by hand. When I then open a new terminal, nothing changed….

UPDATE

As it seems (see here or enter link description here), one needs (additional) tools like transset-df which are very old and not easily available anymore… I still hope someone has figured out a way to have a transparent terminal window…