I wouldn't count on that handbrake much.. that granny 1st gear will be a godsend if you need to slow down fast and the brakes fail.

Depending on your speed, it may not just drop into 1st, but if you double clutch fast and just ram it in there, it'll go.

Then just let off the clutch and WHAM.. you'll go from whatever speed you were going to about 3 MPH in about a half a second.

an idea is only stupid if you think about it rationally.