I saw this singular film double-billed with The Naked Killer (one of my all time favorite movies). Chinese Torture Chamber is weird through and through.
It takes place sometime ago in China's glorious past, when the courts utilized Spanish Inquisition-like techniques to get the truth out of defendants. The opening scenes are a fairly graphic, though oddly funny, demonstration of ghastly tortures.
Then, we are taken to the estate of a rich prince, married to an insatiable princess. He tries to please her by employing exotic "marital aids", but to no avail. She seeks fulfillment through another man. Sexually curious housemaids secretly watch their trysts through holes in the rice paper walls. One is caught, and becomes the subject of the wrathful princess' ire.
Throughout the rest of the movie, as told in flashbacks, this poor maid must prove her innocence of murder (by exploding penis!). The court systematically tortures her and the prince (a suspected accomplice) first by spanking, then through more excruciatingly depicted techniques.
What's odd about all these precedings is that they are simultaneously horrifying, erotic and funny. Kind of like the Japanese film Tokyo Decadence.
Oh yes, there is one sequence that totally blew my mind: The prince spies two heroes flying through the trees, fighting each other kung fu-style, ripping each others' clothes off (ends up being a man and a woman), and then f***ing while still mid-air!
Only Hong Kong could come up with a "porno/horror/fantasy/comedy".