Help Is this SWB + Nitrous Oxide method good enough or is there something i need to revise?

[luna202]

REVISIONED, OPTIMIZED PROTOCOL

Prep:
Fill tub/pool to waist/chest depth. Water temp: 85–90°F (29–32°C).
Pierce all 4 chargers into the bottle.
Wait 60 seconds TOTAL.

Execution:
Stand in the water. Relax.
Sip 1:
Take a deep breath of AIR. Hold it.
Inhale from the bottle for 10–12 seconds.
EXHALE the gas mixture.
Sip 2:
Take a deep breath of AIR. Hold it.
Inhale from the bottle for 10–12 seconds.
EXHALE the gas mixture.
Sip 3 (Optional, if you feel calm):
Take a deep breath of AIR. Hold it.
Inhale from the bottle for 10–12 seconds.
EXHALE the gas mixture.

Final Step:
Take one final, massive breath of AIR.
HOLD that breath tightly.
Submerge your face into the water.
Relax your body. Let the hypoxia take over

suggestions would be appreciated!

 

[Intoxicated]

Pierce all 4 chargers into the bottle.

If the mentioned "bottle" is a cream dispenser (siphon) and its declared capacity is less than 1 L (e.g., 0.5 L or even 0.25 L), then 4 x 8 g of nitrous could create a somewhat excessive pressure inside it. While many dispensers are designed to be fool-proof and can withstand pressures that are significantly higher than those which can appear under correct usage (that is, when the amount of a liquid poured inside is not above the level indicated by the line on the dispenser and the amount of chargers used does not exceed the number specified in the manual for the given siphon), some cheap siphons can be not so forgiving to misuse leading to abnormally high pressures.

Fitness blogger dies after exploding whipped cream dispenser hits her

Consumer journal and family warn of faulty siphons after French woman, 33, has heart attack caused by utensil hitting chest

www.theguardian.com

(Although the article does not mention misuse as a cause of explosions, I suspect that it caused disruption in most such accidents, considering that many people neither follow the instructions nor understand physics well and they don't think about possible consequences of wrong usage).

Execution:
Stand in the water. Relax.
Sip 1:
Take a deep breath of AIR. Hold it.
Inhale from the bottle for 10–12 seconds.

Inhaling directly from a dispenser, especially containing ~32 g of nitrous inside, can be somewhat unpleasant, because the stream of gas coming from the nozzle may be very strong. I know that some people practice inhalation straight from siphons, but this method is generally not recommended.

Final Step:
Take one final, massive breath of AIR.
HOLD that breath tightly.
Submerge your face into the water.
Relax your body. Let the hypoxia take over

I don't get the idea behind inhaling air at the end. Air contains oxygen, which will revert hypoxia rather than produce it. This can be useful when the goal is to fill the blood with nitrous oxide prior to asphyxiation leading to blackout, so that more or less strong N₂O-specific effects could be achieved in addition to hypoxemia; but when the goal is profound hypoxemia, inhalation of air doesn't look helpful.