Water Cooler idea... Your Thoughts?

Right, I will be moving my Dutch Passion plant outside soon enough and am still unsure about Britains on-off weather (Its so hot at the moment!) So I was wondering about when I do move it, if I kept it under a water cooler bottle, (I have cut the bass off and the nozzle bit is still on) would it grow well? I've heard of this technique from a friend and am wondering about it? Also do you advise sticking the plant straight in the ground or a pot for a long while before?
Any thoughts much appreciated!

I would stick it in a pot....if the weather gets too extreme you can always move it.....

but about sticking the water cooler over the pot?

Will it even grow if i have it under a water cooler bottle (with a few holes) outside?