.. thought I would jump in quick before Larry Bible has his 02 cents worth, unless he has fallen off his stool with horror !
. I personally would steer well clear of this idea as regular oil changes will keep the engine internally as squeaky clean as it needs to be. What you will have here is deisel residue left in the engine after it is drained and this will mix with the new oil and reduce significantly the lubrication properties of the new oil. I would guess you would need several oil changes before you finally rid the engine of this diesel. My money is still on regular oil and filter changes, much cheaper in the long run!