Jack Campin: You've been to Sakhalin?
Many times. I spent at least 3 months a year there from 2012 to 2016, sometimes more. Strangely, I liked it (most expats there "endure" it) and hope to get back there some day (next year's looking possible!). I went out of my way to learn Russian, and not to get caught up in the expat community there, so spent most of my time with Russians. This meant that I got out and about a lot more than most foreigners working there.
The bar staff in my local said, in 2012: "You already speak better Russian, after 3 months, than some of the people who've been here 5 years" which I took as a great compliment. They weren't so impressed with my enthusiastic learning of Russian slang from my "Dirty Russian" book...."You want to watch where you say those things and who to....some of them could get you beaten up if you say them to the wrong person".
I met a few Nivkh up near Nogliki, but they're now a tiny minority (less than 1% of Sakhalin's population). Only about 10% of those speak Nivkh fluently, and I've never seen it written, so can't comment on the vodka bottle. I don't recall a lot of "Pts" in the bit of spoken Nivkh I've heard.
The only Russian I can come up with is if the name was phonetically chyoug dush, rather than chugdush, which would make it "iron shower".
A couple of years ago a woman started at my fitness class in UK. I asked where she was from (as she sounded Russian to me) and she said "Eastern Europe". "Where?"...."Karelia"...."Finnish Karelia or Russian Karelia?". She was astonished that I even knew of Karelia, never mind that it spanned two countries. She said she was from a nomadic family and had spent her youth travelling and herding reindeer. I asked if she was Sami: "not exactly"...."Samoyed then?". Again she was astonished that I even knew the word.
Further talking elicited that she'd been to Sakhalin, too: "so do you have Nivkh relatives?" ....cue complete astonishment....."How the hell do you know about Nivkh people?"
She was a real mix, with indeterminate proportions of Sami, Samoyed and Nivkh ancestry. She only spoke Russian, though, with just the odd few words of various north Russian native languages. I try to rub some of the rust off my Russian on the odd occasion I see her now.