Hi Peter.
Thank your lucky stars it's not bunker C. That b****y stuff sticks like the proverbial.
I would think there is some one in 'The Pool' who could advise you.
Washing up liquid is probably as good as anything.
Cheers David.
What is the appearance of water on that patch of timber now? If it is beading, there is clearly some oil left there. If it assumes the appearance of a smooth sheet of water, then you have nothing to be concerned about. Washing-up liquid, a scrubbing brush and plenty of elbow grease should be able to remove diesel without too much trouble.
Peter.