Meatsauce, that price does it include both the tank and the hydrogen? Does it include the regulator? Probably not, nor the hoses. All that stuff is expensive. What would it cost to refill the tank and where would you take it? If you have to send it out to be refilled, the shipping is going to eat you up. A 5' tank is big and heavy. You will not be able to send it usps, and it would be considered hazardous material costing even more. Perhaps have to be sent by truck.
Call me cautious clay but I want to point out that fire is not the only danger here. You can suffocate very easily breathing any gas including helium, nitrogen, etc. Since you are breathing and your co2 is being released, you don't realize you are suffocating often until its too late. Its the co2 build up that makes you gasp for air when you hold your breath. You would just get faint and pass out possibly never to awaken or wake up with brain damage. Breathing it while sleeping is asking for trouble, imo.
If I fill up a glass jar with h2, there is no way to suffocate. I would just sip a little, take in some air behind it and hold. Then breath slowly a few minutes before the next toke since it will take a while to exit the lungs. Water with 2 ppm means a liter has about .002 cubic cm of hydrogen in it. Approximately. Even if you absorb every bit of it, its still only micrograms or picograms of the stuff. Breathing is how we take in oxygen, while I agree we are evolved to absorb o2 and not h2, it would have to come along for the ride given how easily it perfuses our tissues. The one study I saw about using gas spoke of using 2% h2. That means only a tiny bit per breath.
I strongly recommend against using tanks of it with a mask or anything that might give pure h2 and exclude air by accident. If you are going to use the tank, perhaps use it to dissolve in water? What would absorb hydrogen better than water? Anyone know? I assume cold water will absorb more than hot. Perhaps put a little h2 in a jar containing pure water, shake and let it sit a few days? Then you could sniff the h2 off the top and drink the water. It also avoids any contamination from electrodes if going that route.
Maybe we could come up with a better carrier like, I dunno, maybe some oil or other substance that just happens to like hydrogen and will capture more than the pathetic 2 ppm of water.
Overdosing might be an issue come to think of it rather than not being able to absorb enough. I've never heard of hydrogen poisoning so maybe not but it could be a U shaped curve in which you lose the benefits using too much. Or Maybe a curve in which you max out and get no further benefit from more. That seems likely.