A rather short Tantra of only six chapters which speaks of the many travels and spiritual experiences of a man called Vasistha. The work seems designed to combine orthodox Buddhist teachings with those of Chinese Taoism and/or Indian Tantra.
After having worshipped the goddess Tara, and visited the sacred ground of Kamakhya in Assam, the main character finally goes to China (Skt., mahacina), where he encounters the Buddha.
In chapter II he finds the famous founder of Buddhism
contrary to the nature of a person like him seated in a rather erotic environment and
surrounded by a thousand damsels, and drunk.
[Banerjee, S. C. A Brief History of Tantra Literature. Calcutta, 1988. p.237]
However, he is soon told that this cinacara (i.e. the Chinese Way) is proper for one who worships the Goddess. The Buddha also explains that mental worship, and the worship of women are the best types one can practice.
Chapter III of the text states that sexual union (mithunam) is superior to the drinking of wine (madya), and that both should be done only in a sacramental setting, not outside of worship. The text also mentions the navakanya, with slight changes, but actually says that an accomplished woman of any caste may be worshipped.
The text further praises the Yoni Pitha as the best and most auspicious place to do worship. Considering that this Yoni Pitha is the Kamakhya Pitha of Assam (bordering on China, Tibet and Bhutan), we can deduce that Chinese worshippers of the Goddess knew this place and went there on pilgrimage to pay their respects to the sacred stone that is regarded as the menstruating yoni of the Earth.