Its a 50/50 mix. so if your oil capacity is 6 litres then use 3 litres oil and 3 litres diesel fuel. The way it was explained to me (because i was very suspect about this too) is that diesel is oily as well but with the engine oil mix it made a good cleaner while still providing lubrication.
Its literally start and stop the engine 6 or so times and drain it it. But run it (and when i say run it i mean idle and nothing more) for a few minutes at a time. I wouldnt be running it for any great length of time or driving it with this in your engine. It worked for me but you make up your own mind. My engine idled without any weird noises or anything going wrong and actually sounded pretty smooth.
I understand the ill feeling towards putting diesel down the oil filler hole though. Its a strange feeling.
