Dealing with the pesky █ character - I found a rather neat way of inserting it onto a keyboard, and will describe it for my layout.
Photosynthetic seemed to kinda like the idea, hope others find it useful too.
Go to /etc/X11/xkb/symbols and create copy of (i presume you use) US layout (file called us ), calling it say, us_bl
Edit us_bl - pick a key, (i chose <TLDE> the ` and ~ key ) and replace the first, non-shifted value by U2588 (full block, that is), preserving the format.
Eg. for myself
key <TLDE> { [ U2588, asciitilde ] };
Now save the new file.
Edit your /etc/X11/xorg.conf as of following, finding the place where Identifier "Keyboard0" is defined, and underneath, edit following lines, so that they contain the following.
Option "XkbLayout" "us,us_bl"
Option "XkbOptions" "grp:switch"
Eg, for myself,
Section "InputDevice"
Identifier "Keyboard0"
Driver "kbd"
Option "XkbModel" "pc105"
# Option "XkbLayout" "us,ru(typewriter)"
Option "XkbLayout" "us,us_bl"
Option "XkbOptions" "grp_led:scroll,grp:switch"
EndSection
More accurately, add the grp:switch entry if it is absent.
What this does is make you switch between two copies of the US keyboard , one of which, us_bl, has the black character in it, each time you press AltGr (the defined grp:switch defines it as a switching character)
Save, and restart X-window.
Voila, you should now have a keyboard ready for easy expungements.
