DERG - Modern engines are cleared to use a wide variety of fuels and additives. We say 'fuel'. Not sure what kerro is, or paraffin in this context.
But I am very impressed by the power of your imagination in putting together a scenario whereby oil manages to make its way to the combustion chamber and upset the combustion process to such an extent that hazardous vibrations leading to shaft disconnect result.
I'm with Barit on this and consider it a very unlikely explanation.
But do tell us how you think the oil arrives at entry to combustion chamber. I think I may have asked this before but may have overlooked the explanation.