Finally got around to making a fly-swat style static grass applicator.
I used a cheap fly-swat from Mitre 10, removed the mesh and replaced it with $2 shop metal sieve soldered to the connection for the wire mesh. The other wire was connected to a longer piece (the red wire you see above) and to a nail which is driven into the module, once PVA is painted on where the static grass is to be applied, e.g.:
Pretty happy with the results, although in this scale it's much harder to see the grass standing up.