Manos is breaking the law and causing an offence under the Water Resources Act 1991. What he has done is potentially punishable by an £20k fine and/or two years in prison.
Do not become a misguided sheep and do the same as he has done.
He is totally wrong in assuming diesel is biodegradable. It has hundreds of OTHER chemicals which clean and protect the engine as it is used.
Contary to Manos's protestations Diesel and its additives are carcenogenic and are well know for triggering Cancer in Humans.
The statement that the Exon Valdez Disaster has promoted marine life is also eroneous.
The oil kills all the non tolerant species and causes a flourish of growth in the tolerant species which will eventually cause the tolerant species population to reach unsustainable levels and collapse killing even the tollerant species in the long term.
Look at for info on a similar case;
The best method is to rinse off with lots of water or keep your car out of the salt water! (A company called Marlow make this amazing device called rope!)