They look good. There are chargers that contain special additives which are supposed to add a specific taste to the cream, and such chargers should probably be avoided, because you need just pure N2O.
How would you actually do it though?
Firstly, I gonna use a few chargers in order to produce euphoric feelings and displace almost all air from the dispenser. For this purpose, I'll use a latex balloon instead of a plastic bag. Inhalation of the gas is supposed to be done through the mouth in this case. Then I gonna attach an empty trash bag to the output of the dispenser, secure it with a few layers of electrical tape (so I won't need to hold the bag with my hands), and then start the procedure of filling the bag.
Sorry if this seems stupid, i clearly need to do more research- but surely one charger wouldnt be enough..
Each 8g charger contains the amount of gas which expands to approximately 4 liters at the pressure of 1 atmosphere. Therefore, for filling a bag with the volume of 20 - 30 liters I will need 5 - 8 chargers.
How would you get the gas from multiple chargers
The safety precautions imply that whenever a dispenser is filled from a single charger, the gas should be released from it prior to using the next charger to refill the dispenser again, so I wouldn't ever try to fill the dispenser with several chargers without releasing the gas in between.
The input screw (where you place the cap with a charger), the output screw (where you attach the bag) and the trigger of the dispenser are separated from each other, so there is no any unhandy interference between filling the bag and putting new chargers. All you have to do is to put a charger into the cap (which should be in the kit containing the dispenser), screw the cap (as shown on various videos about making whipped cream), then pull the trigger (hold it until the gas is released), then unscrew the cap, remove the charger and repeat.
I'll probably also wear gloves, because the dispenser will become very cold after a series of filling-releasing operations (it becomes noticeably cold even after handling a single charger).
When the bag is filled sufficiently, it makes sense to wait a few minutes till the gas becomes warmer. When the bag with N2O is completely ready, hyperventilation is performed and the bag is detached from the dispenser. Then the bag is carefully placed over the head while holding breath (prior hyperventilation is supposed to increase the time during which breath holding can be carried out comfortably) and sealed around the neck as outlined above.
After the bag is secured around the neck, breathing is resumed in the form of deep inhales and deep exhales. Note that these inhalations probably won't cause euphoria nor contribute anything remarkable to the euphoric feelings caused by prior consuming of N2O, because this effect needs substantially more time to develop than needed for reaching unconsciousness from hypoxia.
When N2O is used for producing rapid unconsciousness, the perceivable effect may be indistinguishable from that of plain inert gases like argon. N2O may reveal its advantages when it's consumed recreationally beforehand and when its additional sedative effect could play a significant role in preventing or mitigating discomfort in case if hypoxia alone would not suffice for suppressing perceivable symptoms of hypercapnia induced by accumulated carbon dioxide (this may happen if the concentration of residual O2 is much higher than should be).
If you live in Australia and have a hot weather there, you should pay attention to proper transportation and storage of N2O chargers. The critical temperature of N2O is 36.4 - 36.5 °C. When the temperature is below this critical point, N2O can exist in the liquid form with the pressure of vapors at most 71 - 74 atmospheres (different sources provide slightly different values of the critical temperature and pressure).
N2O chargers are very small (approximately 10 ml each) and normally contain N2O in the form of fluid inside. However, if the temperature goes above the critical value, this substance may become supercritical fluid whose pressure can grow to approximately 400 atmospheres or even more. Although some manufacturers claim that their chargers can withstand temperatures up to 50 °C without rupturing, I wouldn't really want to check this, and I'd advise to not let your chargers be exposed to heat above 36 °C at any time (holding a charger in bare hands for a few seconds should be safe).
After buying a dispenser, I recommend to wash its insides and dry (do not use any extra heat, because dispensers may have sensitive plastic cover inside).
