What a find! The Power Of The Witch is a documentary about witchcraft as it was practised in the late 60s and early 70s in the UK - apparently it was only screened once and there is practically no information about it on the web. From the uploader taitsitarot‘s YouTube description:

An extremely rare documentary about Witchcraft aired once in the UK in 1971. Featuring contributions from Eleanor Bone, Cecil Williamson, Alex & Maxine Sanders [above], Doreen Valiente et al. Very much of its time and with some very rare footage, also includes reference to the famously unsolved murder of Charles Walton on Meon Hill.

The Power Of The Witch is worth a watch even if you are not particularly interested in the occult - rather watch it as a document of its time, capturing as it does people’s attitudes, beliefs, fashions and plummy Brit accents. It’s a curious mixture of patriarchal stiff upper lip-ism and unerring belief in both Christianity and the forces of magic, making it feel very much as if it comes from a completely different era. Not to mention, it’s a goldmine of potential witch haus footage:
 

 
Thanks to Seth David Rodriguez!

Proof that use of bodily fluids common in ancient folk spells. From New Scientist

A rare insight into the folk beliefs of 17th-century Britons has been gleaned from the analysis of a sealed “witch bottle” unearthed in Greenwich, London, in 2004.

Witch bottles were commonly buried to ward off spells during the late 16th and 17th centuries, but it is very rare to find one still sealed.

“So many have been dug up and their contents washed away down the sink,” says Alan Massey, a retired chemist formerly at the University of Loughborough, UK, who has examined so-called “magical” artifacts and was asked to analyse the contents of the bottle. “This is the first one that has been opened scientifically.”

During the 17th century, British people often blamed witches for any ill health or misfortune they suffered, says Massey. “The idea of the witch bottle was to throw the spell back on the witch,” he says. “The urine and the bulb of the bottle represented the waterworks of the witch, and the theory was that the nails and the bent pins would aggravate the witch when she passed water and torment her so badly that she would take the spell back off you.”

London’s magical history uncorked from ‘witch bottle’