Scientifically it is possible. I mean cells break down, go through apoptosis, necrosis, all the time. Whose to say a sperm cell cannot go through the same process? I mean here is literally an article describing the apoptosis of spermatozoa (https://pubmed.ncbi.nlm.nih.gov/23784837/). After apoptosis, a cells constituents are basically broken into their most basic substrates, building blocks, and used elsewhere in the body. Its definitely not an unheard of process. Through research in Yogic science, I see a few herbs really are used extensively for inducing this effect. The main cycle the Yogi is trying to perpetuate is to kill the sperm cells itself, and then reabsorb the energy from that cell by making the normal cells "hungry" in a sense. The sperm is considered the endpoint of biological life in males, it is the main purpose of male biology; while in the female, the egg. The transmutation is the process of converting that raw life energy into a higher potential for your overall life, its something they call "Ojas", I think the TCM translation probably would be Shen of the Three treasures. Its like an energy that engorges the cell and makes them function at a higher level with ease. Its like the oil in an engine, both in the physical sense, and metaphysical energy sense. Some herbs that do this: Neem - Kill Sperm Turmeric - Helps Dilate, or make normal cells hungry for that energy. I've also need the Tulsi tree leaves used as well, there is studies that show it does kill the sperm while increasing overall testosterone. Maybe another physical biproduct. From my own examination of the effect of these herbs, it does indeed make the body feel good. But for some reason in me sex drive increases. In my mind, I kind of affixed it to that effect that happens with males up to 7 days after ejaculation, where our testosterone rises, LH rises, FSH rises, etc and sperm production increases - there are studies about this online. But I feel with the neem/turmeric it causes a more prolonged, or elongation of this same cycle, so your bodys naturally producing huge amounts of sperm continuously, after a certain amount of time on this regimen, but instead of getting depleted, the energy gets reabsorbed. Kind of like a metaphyiscal biohack.