From the tantrik commentary by Curwen (quoted in Beyond the Mauve Zone):mamsa still continues to be flesh; meena still floats like fish in the water by which it is surrounded; mudras are secrets to all but initiates and cannot be communicated ecept by word of mouth and face to face with the Guru; and maithuna alone can rejuvenate her after the exaustion of the Puja.
Grant continues:The wine or madhya is the urine of the Suvasini after the Fire Snake has absorbed the amrita or nectar of the ultimate chakra, Sahasrara. This nectar or soma is the ‘moon-juice’ of ancient Vedic lore. The flesh, mamsa, is the lunar emanation embodined in the menstrual fluid at a certain stage of its flow; and the fish (meena) is a secretion that swims in the waters of the lotus-pool. The maithuna is the mystical congress of Shiva and Shakti — Consciousness and its Power — in the Sahasrara Chakra.
[…]For the fully initiated Kaula Adept, the universe is a manifesation of perpetual joy, bliss, Amrita (deathlessness), from which he distils the elixir of immortality. Liber AL, today, echos his paen of rapture: Remember all ye that existence is pure joy; that all the sorrows are but as shadows; they pass & are done; but there is that which remains.
[…]The final bija, Krim, is the bija-mantra of Goddess Kalika, the hidden Principle of Creation described in the Ratrisukta as ‘Night.’ She it i who reveals the universe as a shadow (chaya). She is the reflex of all colours (kalas), Herself ‘without colour’; black. Yet is She the background of light, and the crescent (shashi-kala) on Her brow denotes that She is the originator of nada-bindu-kala, the trikona at the center of the Sri Chakra. When fully self-expressed She appears as Uma, with the glamout of the full moon, and is then known as Sri Vidya. Her essence, however, is always Ama (darkness). Uma (light) and Ama (darkness) are the twin poles between which flashes the vibration AUM. As Japa of the bija-mantras leads the Fire Snake progressively higher, do do the energies released in the lower chakras, bordering the subconsciousness, become increasingly active.