A question on scotch

[Pyrrho]

For cheap inebriation with minimal regrets, someone once recommended to me sending cheap vodka through a Brita filter...

I would instead recommend something like 190 proof Everclear (not available in all jurisdictions):

https://en.wikipedia.org/wiki/Everclear_(alcohol)

You will need to mix it with something, as even a 50-50 mix with water will make it stronger than the typical scotch (though for taste, one may wish to mix it with something else, like 7up or ginger ale or coke or whatever).  Per ounce of alcohol, it is very cheap.  It does not have much in the way of impurities to bother one, as it is about as close to pure alcohol as you can get.  And one does not have to get a filter.