This is quite a creative method lol but ironically isn't that bad. Its greatest advantage is that you basically lie down and just wait until you feel very tired and fall asleep.
The downsides with this method are mostly about cost and practicality but for a determined individual willing to make it work it's not a bad idea.
First obstacle is getting such a big freezer, preferably large enough to lie down comfortably. Fortunately you can source one second hand as large and bulky items like these are something people would want to get rid of to save a trip to the junk. You would also require some help transporting it and moving it wherever you intend to ctb, which would involve people involuntarily helping you to ctb.
Second step would be to controlling how the gas is released and controlling the gas flow. Stepping in with a cylinder doesn't sound very appealing and is susceptible to damaging the regulator valve.
I would recommend multiple outlets of gas with external cylinders outside the freezer, near the bottom in the sides preferably to help push out the remaining oxygen. Then set the appropriate gas flow on all cylinders and climb down awaiting your destination.
Check valves will help bleeding the excess oxygen out while keeping the overpressure under control.
What kind of gas and how much?
I found one freezer which would accommodate a shorter individual like myself with an interior volume of 635 liters. I have no idea how much gas is needed but four times the internal volume wouldn't be that crazy? Two 2000liters of inert gas at either side of the freezer would sound appropriate and possible to source without being suspicious.
2000 liters at 25/lpm would last you 80 min per cylinder, giving you 50/lpm with both cylinder on. 50/lpm would fill up the 635 liter freezer in 13 min, hopefully lowering the breathing atmosphere to make you fall unconscious. The reaming 67 min would with high certainty make you ctb. A test with an oxygen meter before hand would be a sensible precaution.
Then the question about which gas to use.
Argon which is a heavy gas would have the benefit of sinking to the bottom of the freezer and pushing the oxygen out. It would be a matter of keeping the lid open flooding it with argon, then jump down to an highly concentrated argon atmosphere down there. You would lose unconsciouses pretty quickly and is probably the safest bet to ensure ctb.
Nitrogen, the preferred gas for sarco does not have the same benefits of argon in this case. You would have to wait inside the freezer until the atmosphere is low enough, which would be approximately 13 min, the same time as with sarco. Some could call this an advantage as you simply wait until you fall asleep, wouldn't recommend the same procedure with argon since argon poisoning is more noticeable than nitrogen.
Helium the most expensive gas would have similar results as nitrogen. I'm unsure how well the helium would work with the check valves? Would helium the lighter gas have problem pushing the ordinary air through the valve? Since helium is more expensive nitrogen would be preferred between helium and nitrogen.
An intriguing idea with a freezer I must say, giving the same benefits of an sarco with some DIY solutions and handwork. I'm almost interested doing it myself, but I settle with the ordinary way with a mask.
