Knurling on the lathe

Among the non-professional machinist community there are two schools of thought on avoiding a "doubled" knurl. One school, the one to which I subscribe, calculates the workpiece diameter needed to prevent doubling*. The other school uses the "mash it in until it starts looking correct" technique. What are your thoughts on the subject?

Also, I've always (even with brass) flooded the work with oil while knurling to flush away the tiny flakes of metal thrown off by the deformation induced by the tool. I don't see that being done in the video.

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* This calculation determines the workpiece diameter needed to make the workpiece circumference an integer multiple of the pitch of the knurl wheels.