As a chemist I really enjoy this. It only gets scary where he details that you can buy HF hydrofluouric acid over the counter... That is interesting to say the least. Can't buy that anywhere here...
He didn't purchase lab grade HF, it's "just" commercial "Whink Rust Stain Remover". In all countries, buying customer chemical products is always a way to bypass the regulation and get otherwise hard-to-obtain chemicals, as long as you know where they can be found. Though, selling chemicals in general is less regulated in the U.S, getting the same "Rust Stain Remover" in other parts of the world is certainly more dif…
In certain countries getting Sodium Biflouride (such as from armor etch) is easier and it readily turns into HF. Of course you should however still obtain the relevant licences, in the UK this is the EAP licence and it lasts for 6 months and is fairly straightforward as long as you've never been convicted of a crime.