Rather than telling you that you shouldn't be doing this (and I really think you shouldn't just as it seems everyone else replying appears to feel), here's what I suggest:
Learn speed and aim separately. Once you've gotten the aim down, speed is pretty easy to gain. However, if you only want to pass maps then learn speed first (play easy maps with DT) and the play the map you want to pass repeatedly until you fluke the aim and eventually pass (not likely if you play a map that is actually hard throughout and is longer than a minute and a half).
Learn speed and aim separately. Once you've gotten the aim down, speed is pretty easy to gain. However, if you only want to pass maps then learn speed first (play easy maps with DT) and the play the map you want to pass repeatedly until you fluke the aim and eventually pass (not likely if you play a map that is actually hard throughout and is longer than a minute and a half).