Heere's the recipe from my book:
Crush 2 bulbs of garlic - the whole head not a clove.
Boil briefly to soften in 1litre (2 pints) of water
Strain and top up mixture to 1l(2pts) again. Leave to cool
To use stir 1 tablespoon into 4.5l (1gall) of water sprinkle onto foligae and allow to dry.
Here's the fun bit:
Apply in dry weather so the rain does not dilute the wash. Reapply every 2 weeks
Rather than beer for traps it says use a mixture of yeast and water and drink the beer!