Complex sentence: Traditional Egyptian practice involves pressing the plant material, and then burying it in unglazed ceramic vessels in the desert for a period of months to drive out water, the water having a smaller molecular size diffuses through the ceramic vessels while the larger essential oils do not.
Split into simpler sentences: Traditional Egyptian practice involves pressing the plant material, then burying it in unglazed ceramic vessels in the desert for a period of months to drive out water. The water hase a smaller molecular size, so it diffuses through the ceramic vessels, while the larger essential oils do not.