How are you dealing with Greenfly?

If you keep these in pots then when covered in the little horrors just dunk the infested plant upside down in soapy water to remove the bulk of the pests

I'm loving this idea, think I might take it up as a new sport 

Im  finding it hard too,  with it being hot have been leaving green house door ajar during the day and in they fly ,my tom plants were covered sprayed with bug stuff and does seem to kill off any new ones that appear for about a week or so .My problem is instructions for bug killer says to only use 3 times so will not be able to use it by end of month.I did try soapy water but didnt find it very affective to be honest.