Black fly and greenfly!!

Oh my word! I woke up very early this mornig and had a coffee in the garden. To my horror, I have been invaded overnight by blackfly on my cucumbers and what i think might be greenfly on my pepper plant. The pepper plant is by far the worst affected and is smothered in the little blighters! I did a search and found out the est cure is to spray diluted washing up liquid on them. I have just done this, but I am now worried i may not have diluted the washing up liquid enough as i do admit i was a bit heavy handed with the squirt i put in the spray bottle.
Will this affect the plants?

Thanks Mick. I shall give that a go, but i am still worried i may have sprayed too much washing up liquid onto the plants.