This nectar when produced, drips inside the mouth and is sweet. Initially it can be even salty. But it is mostly sweet and delicious. :) It is very well tangible. It gives the yogic practitioner a very beautiful state of mind and makes the body disease free. This nectar is even expected to transform the physical body into an immortal body if there is enough of secretion. But, the alchemy of transmutation of physical body is a slow process. Probably if one lives long enough, this could be achieved.
This nectar is produced when the sexual fluids are transmuted into subtle form of energy through yogic practices like kriya pranayama in which the breath is rotated inside the sushumna. When one is properly moving the prana inside the sushumna, one can easily feel the warmth in the sushumna channel which is part of the subtle body. This process naturally happens in every person in natural states of happiness or excitement. If an artist is involved with the art, this process of transmutation may naturally happen. The yogic practices are just tools to speed up this process by many fold times. This process also happens powerfully with sun gazing. When one wants to try sun gazing, the duration has to be increased very slowly. Otherwise, it might disturb the eye sight. The process of transmuting with mind/breath is a safer and effective technique which I would recommend. So, should one refrain from having sex? It is not a necessity if one understands love making in the tantric way without wasting the essential fluids.