Hmm does seem to work, but as you say ridiculously huge. Well not ridiculous obvioulsy, but very big.
Bloody obvious maths actually. I clearly wasn't thinking well that night, I spent years doing that sort of maths. I've got to stop doing even basic physics/maths in late night posts. I make far too many fundamental mistakes or just miss stuff entirely.
Still just do it in a micro second and you can get to 0.1c in only 150m. You are accelerating the slug at ~3E12m/s/s admitedly but that small technical problem aside it's a fine plan.
