I use Rhubab leaf water, problem is that after a heavy rain fall the smell is washed away, you can actualy watch the bugs try to land then move on.
Pass the leaf water through a filter like " ladies tights " or an old HGV air filter so that it pours through the rose of the watering can for longer without blocking it up.
Seen it on TV, works for me, easy to apply.
All the best to all,
FP xxx