Personally I think the "operation" is just a further elaboration on what has gone before. In verse 25 R.H.K. gives two alternate uses for the ingredients. Incense to burn or Cakes to eat. Later in the same verse he tells us that the incense/cake ingredients have another use. I interpret this to mean that you don't have to burn or eat the stuff right away. You can hold off for a while and charge them with the "perfume of your orison".
The result is that "it shall become full of beetles as it were and creeping things sacred unto me." Like I said before, I don't think this is meant to be taken literally. (Indeed this applies to so much of the third chapter where the symbolism seems to seduce the reader into literal interpretation on many points.) I think it is most probably a reference to Atu XVIII The Moon. The metaphorical beetles may indicate those inner enemies that automatically rise to the surface of consciousness in anyone who tries to pursue the Great Work. The symbolism may also indicate the qliphoth too. These can slain by naming and then burning the incense. Or, if it is a cake, eaten. After all tradition is full of lore concerning the power of consuming an enemy. In this case it is not quite so literal as eating the liver of a dead enemy, but the intent is still the same.
But why should the incense/cakes be a magnet for these "beetles"? For some reason 1 Corithians 15:50 comes to mind.
I'm sure P.F.Case links this verse to Atu XVIII somewhere.
I know that Crowley mentioned a literal manifestation of this verse (AL III:25). But I believe he never said anything about beetles appearing in his Cakes of Light. He just said that on one occasion strange beetles appeared around Boleskine.
Just out of curiosty this question is aimed at anyone who favours a literal interpretation. In the absence of beetle eggs or larvae, how are beetles able to spontaneously manifest in anything? (Please don't say magick.
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