Those moss recipes will work, BUT:
using a low pH clay will work equally well. (pH = or < 6)
The reason the beer, milk, sugar, whatever is used is to facilitate bacterial fermentation and growth. The various acids produced by the breaking down of the organics (sugar, milk protein) help to break open the moss/fern spore outer layer. The excess H+ ions attack the outer shell of the spores and allow for the gametophytes to be released. A low pH clay soil will do this equally well as the soil particles and humic acids present will provide the needed H+.
I only bother saying this because those recipes yield sizable bacterial fermentation which smells downright awful. I used this method myself until I thought about WHY this folk method works and found that its not really necessary so long as you still provide the H+ ions. I've gotten equally good results using a low pH clay "mud" that doesn't yield the nasty smell and it gives something for the moss to grow in that isn't bacterial/fungal laden sludge.
Resco "Redart Clay" typically has a pH from about a 4-6 and works well. Just remember you have to keep it wet, calcium kills moss (be careful if calcium dusting), and the larger and better quality the starter colony or spores you use the better.
Good luck and give it water, time, and tons of light.