To activate the blood cleaning command, turn on the console with the (~) key and then enter the following command in it, which will help in removing blood from the map. The command also cleans the remains of grenades as well as traces of bullets left on the walls.

r_cleardecals

Bindy for blood removal:
Cleaning under Q - bind "Q" "lastinv; r_cleardecals"
Cleaning for reload - bind "R" "+ reload; r_cleardecals"
Cleaning under shift - bind "shift" "+ speed; r_cleardecals"
Blood removal under ctrl - bind "ctrl" "+ duck; r_cleardecals"
Removal of blood under W, A, S, and D.
The following commands will make the blood disappear when you press the W, A, S and D keys, i.e. when you move around in CS:GO.

bind "w" "+ forward; r_cleardecals"
bind "s" "+ back; r_cleardecals"
bind "a" "+ moveleft; r_cleardecals"
bind "d" "+ moveright; r_cleardecals"

Undoing the above binds:

By using the binds below, you will restore the basic setting of the keys and turn off blood removal.

bind "Q" "lastinv"
bind "R" "+ reload"
bind "shift" "+ speed"
bind "ctrl" "+ duck"
bind "in" "+ forward"
bind "s" "+ back"
bind "a" "+ moveleft"
bind "d" "+ moveright"