What's more, they're leading small (?) quantities of hydrogen into a metal container which (presumably) hasn't been vacuum-emptied beforehand, and so will after a while contain an air+hydrogen mixture, which while technically not oxyhydrogen, can still be ignited and make the metal gas tank explode like a pipe bomb.
The first time I tried to write this comment, I was a little flip, because I'm not sure if you're trolling.
Purging the container is very easy and requires nothing more than fire (which I think Africans have), water (I am sure they have this), a vessel for boiling the water (ditto), and a moment's thought (the linked article seems to suggest this is locally available too). It does not require any vacuum pumps.
Step 1: Fill the vessel with water and start a fire
Step 2: Fill the hydrogen container with water and invert (so the open side is down)
Step 3: Hold the hydrogen container so that the opening is just below the surface of the water-to-be-boiled
Step 4: Wait for water vapor to fill the hydrogen container.
You now have a hydrogen container filled with water vapor and trace amount of atmospheric gases (the ones dissolved in the water and the ones adsorbed to the surface of the container). Since the urea electrolysis process produces only "dryish" hydrogen gas (the borax stage is used to remove water vapor from the as-produced hydrogen), it does not matter that the hydrogen container initially contains water vapor.
At this point, the user can either cap the hydrogen container (which will produce a poor vacuum as the water condenses) or immediately start filling it with hydrogen.
If conservation of borax is important (probably not, since I suspect that it can be dried fairly easily) one could prime the system by purging the hydrogen container with as-produced hydrogen to reduce the water content to an acceptable level before connecting it to the borax stage.
