Do Magnitsky Laws actually work?

Canada, in concert with the US, UK, and EU, is on a roll recently as regards imposing long-overdue sanctions on China and on Russia. These are Magnitsky-style sanctions on individual officials, rather than on the country as a whole, but I can't help but question how effective such sanctions are in practice. 

I can see how countrywide sanctions could effectively hurt a pariah state, but how is slapping sanctions on individuals (and, note, the individuals sanctioned are not leaders, but "officials", mid-level functionaries at best) going to change the way those states behave? In many cases, I am not even sure how the individuals involved are discommoded at all, let alone the countries as as whole. These sanctions involve freezing any assets these individuals have in Canada, banning them from travelling to Canada, and banning Canadian citizens and businesses from providing them with financial services. So, unless these people have offshore money lodged with Canadian banks, or cottages in Muskoka, or plans to visit the Rockies, how are they going to be directly affected at all? China's knee-jerk sanctions back will presumably have even less effect.

I can understand that there is a certain, limited, diplomatic impact - take that, you varlet, see how cross we are! - but  I can't see this having any effect at all on the likes of inveterate offenders such as Russia and China. They are not going to turn round and say, "oh, sorry, I didn't realize you were so serious, I'll change our polices at once!" 

It's hard to find data, or even opinions, on the matter. It's almost as though Western democracies have taken it as an article of faith, and closed ranks around the whole concept. Probably the best exposition and assessment of the arguments I have found is this article from the Sydney Morning Herald.

Bill Browder himself - anti-Putin zealot and architect of the original Magnitsky Act back in 2012, who has spent his life ever since flying around the world trying to persuade other states to enact similar legislation - argues that making officials who were involved in specific civil rights abuses or corruption scams into international pariahs in this way works, and also has the effect of making other officials think twice about getting involved in similar schemes. Says Browder, "It's creating a new culture around the world. A general in Belarus might think twice when they're given orders to commit atrocities. And it will only get stronger the more country use these sanctions." He also says, "It's not enough, but it's something." Human rights lawyer Amal Clooney adds, "You many not be able to solve every problem in the world or respond to every abuse, but you can make sure that your country is not a safe haven for despots and war criminals."

And maybe they're right.