and if the sun doesn't work?

the hose? or am I being thick?

I think perhaps an empty spray bottle or one you get for spraying plants with

That's the one, I got 2 in pound world (2 for £1 that is, in the gardening section!)

Excellent thanks for the tip, I just assumed keeping them in the sun for as long as poss would do the trick, will get a spray bottle

I use a spray bottle too, and sometimes you have to give it a couple of days, but they should eventually go!