Chris,
The hollow tine aerator works well. I guess this is the type of thing
you are on about http://www.mower-magic.co.uk/acatalog/hand_tools.html

The springs don't actually push the plug out, its the next impression
that does, they aid the movement of the trough, which rides up and
down. You can get some that areound the £20 mark, that dont have the
collector trough, that just act as borers, which work just as well.

After making your holes every 6ins you will be fed up! Then having
gone to the trouble of making holes you fill them in - you want to use
a sand mix to improve the drainage. You can mix your own - anywhere
from 60-80% sand. You can use loam / coir / peat or a combination
thereof for the remainder.
http://www.rhs.org.uk/advice/profile...utumn_lawn.asp
Clifford
Bawtry, Doncaster, South Yorkshire