i'm finding this a bit tricky too with my solo archer (i 'hired' a thief to open the door

)
it seems to take a while to take effect and then is very short duration, and like you say, there's no icon or animation for it so its easy to miss and the action is easy to cancel if you don't wait long enough - i'm fairly sure i did get it to work though
all that is only based on observation though - don't take it as gospel (and i did have boots of speed on - that's worth testing)