Permastat was the spawn of the devil. EVERYONE used too much and its self-limiting aspects weren't that good, so loads of gunge would come off on the stylus with every playing. Ghastly stuff. I had more luck with the similar "Soundguard" treatment which was appied in a similar way.

A few years later, the Hunt P2 formulation, based on a dry-cleaning liquid (Halocarbon 113 apparently as analysed by an industrial chemist we had as a client) was set to try to remove all this gunk, together with the mould-release agent in the grooves. The difference to treble quality was astounding and, on album tracks I had an acetate for, the treated discs sounded more like the master acetate, so a "plus" in my book. Even P2 wasn't without its problems, surface noise sometimes increasing.

As to the Cantorion cleaner, I can vouch for it as it seemed to give the best of all the prior treatments, reducing noise but seemingly increasing clarity too. I did buy one, but CD reproduction and "life" got in the way of me trying it properly, and the kit was ditched when my Dad moved and the family home was cleared out.