What do some of the men snort up their noses from small white bottles during sex?
Cum of course 
I’ve only seen Artem do this it must give him some kind of fuel for when he’s having sex (no sorry he doesn’t know how to have proper sex) when he’s jackhammering a poor girl
definitely the popper at least that they are cooled and use some medicine …
Poppers are cheap and easy to acquire, often sold as a room deodorizer or as sex enhancers in sex shops, although their use carries significant risks. With brief, intense effects lasting from just a few seconds to a few minutes…
I would need a barrel of the stuff 
The substance in the white bottles specifically, are used at various times by a few of the participants and is just a simple nasal spray, which perhaps quite surprisingly is often based on sea water. It seems this helps with comfortable breathing in the atmosphere they are living in. The poppers referred to, in the comments on your thread, are quite different but are indeed used by some people on the cameras, occasionally.
It seems like it’s only of the guys that use it and it’s always during sex. That’s why I ask. I know what poppers are and they aren’t poppers.
I’ve seen Wayne/Gojo do it constantly - did it at least 3 times within 5 minutes while fucking a girl at Connor and Wynona’s old location a few weeks ago. Connor also did it a couple of times that night. 
I remember once in the middle of some ‘fun’ with a guy, we sniffed some poppers. He had an epileptic fit. The bad part of my brain was like ‘I should take advantage of that thrashing and hip thrusting’ but the good part of my brain said ‘no, cradle his head’ and made a mental note to ask about epilepsy before giving the bottle to future partners in ‘fun’. Fortunately the fit was only mild and he was fine afterwards. Oh how we laughed …
Well hopefully I have now (well with my previous comment), answered it once and for all. 