i agree with @My_name_is_Luka, as i began with studying the methods, i saw the bag method which seemed very promising..
i also read on some sites this method will induce the tunnel and light/god phenomena etc.. but now, 1-2 years later im sure this phenomena will happen with every method.. anyway, so as i began searching for the right helium shop, this in it self was not that easy since you must use a gas with certain purity etc..
i also had trouble calculating how much gas actually was needed, at that time it was just way too much effort, on top i also had to find the right cylinders, and i only found very high priced shops, additionally it wasn't easy for me to order things since i was living at my parents..
somehow i discarded this method, maybe im just too inpatient and exhausted to figure out all that stuff but if i had all that equipment for this method i would definitely prefer this method over sn, since its pretty safe and peaceful, if you figured everything out applied everything correct...