Scaling down is quite difficult, I've never mastered the Ashoka base because the amounts given are far too much for me and trying to reduce it doesn't work for me. I had the same thoughts with this, even if you do 1/10th you are still going to end up with about 2 litres, which is a lot of garlic sauce.
Would be very interested in others' thoughts/experiences with this one.
Cheers
CoR.