I've been making curry sauces based on coconut milk,
and I can't detect any flavor from the lemongrass.
I crush it with the flat of my kitchen knife, and
simmer the crushed lemongrass in coconut milk for
20-30 minutes. I think I used five stalks of it
last time. I peel off the outer layers and trim
a little from the base end. I use about ten inches
from the base end, cut into two five inch segments.

What's the problem? It's really crushed, and last
time I followed up the crushing with a beating from
the back edge of the knife. Maybe I need to simmer
longer? Maybe the coconut milk is muting the flavor?
(It seem to mute curry powder quite a bit.)