Some sort of “secret formula”, the label has been removed from the squirt bottle, or a “solution” has been transferred to a non de-script bottle, so who knows. There are so many products on the market. That one looked super easy to get results. He had some fairly heavy duty gloves on; must be rather toxic and risk of skin damage. I would say that is a white pad with applicator.
Most likely it is one restore. I think it’s funny how he insulated that all window cleaners use a razor to remove hard water. I don’t like to use acid on the windows because it can leave an orange peal texture on the window.
The color appeared green on the standard white pad, which I believe looked like Bioclean to me (it is a medium-duty acid/abrasive in my book). One restore is not a paste (unless someone has added something to thicken it but its always been a liquid for me) Thats another reason I think it was BioClean. Anyways what i always found with BioClean was imo it left too many micro-scratches after use (i don’t know why) and I tried many different ways of applying it to varying degrees of damage that I encountered on jobs. I did like that you didn’t have to be as careful with it as with OneRestore or CC550 (in the sense that it is a milder acid compound). Liking the 10in washer though
Just starting into glass restoration, out of some of the commercial products ive used here is a starting point
mild abrasive - Titan A-1
medium acid/abrasive - BioClean
all-around acid - One Restore (might still decide to watch for tin side especially in higher concentrations)
heaviest you can go acid-wise - CC550 (others may know of something more or just go with the base ingredient"s")
Now i just use Mr. Hard Water polishing kit and have the Glass Renu for anything deeper (ive used the pads 1 time so far) (these are good commercial options) and there are many users of cerium oxide + various pads or other compounds as well…just as @Henry