Ok. thanks for the help everyone.
I'm feeling slightly victorious (the change in weather probably helped...so we'll see in a few days time when it's supposed to rain again...).
Although there are a few persistent bastards who just refused to die, I did get satisfaction in waking up to find hundreds of slinky Portuguese corpses on the doorstep.

I also tried the suicide trick....half buried a container with water next to the outside light, which worked quite well.
The only problem is I peppered the front yard with the bug powder, but not the back...now they are getting smart and have started coming round the back of the house. Goddamn counter intelligence.

I tell you, my hatred for this species is increasing. As if it weren't bad enough squishing them in to the carpet every time I walk through the hallway (and also as Jester pointed out, they are in fact illegal immigrants), I nearly inhaled one that crawled up the side of my pint glass of whiskey and coke. He promptly found himself in the nail clipper guillotine.