Stand on the spot where you want to throw the smoke, stand still, aim, hold mouse1, press space to jumpthrow.

bind space +vthrow
bind ctrl +vduck
bind mouse1 +m1

alias +M1 "-use;+attack;alias checkatk +attack"
alias -M1 "-attack;alias checkatk;spec_next"

alias +vthrow "-attack;-attack2;+jump;+duck"
alias -vthrow "SPEC_MODE;-duck;-jump;checkatk;checkduck"

alias +vduck "+duck;alias checkduck +duck"
alias -vduck "spec_menu;-duck;alias checkduck"

alias checkatk ""
alias checkduck ""