I don't know of an actually tested formula, but I have used the "moss
milkshake" several times and have successfully introduced moss
onto two Japanese concrete lanterns and several rocks. It does take
several years before a decent colony is established though. Anyway,
I simply took a handful of moss growing in the garden and added milk.
I used different types of moss; for example, moss growing beneath trees
amd moss on the lawn. This way I thought I had a better chance of finding
a moss that would do well in the new location. I sometimes used sporophyting
moss and sometimes not. I don't think it matters because many moss can
reproduce vegetatively from gametophyte fragments, sort of like taking
cuttings. As for the milk, I use whatever was in the fridge (past due date, 'cause
I'm cheap). I've never put it in a blender. I just break up a handful of moss
into a large cup/mug. About a pint size (half a liter). I fill up the mug with milk.
Swish it around with a fork. Take slurry to the new moss site. Dripple it all onto
the rock or Japanese lantern. I leave the clumps of moss on the rock or lantern.
It looks messy.
The only secret I can pass on is that moss needs a moist place to grow. Thus,
the moss has taken well on the north side (no kidding, the boy scouts were
right) of the Japanese lantern roof but not on the south side.
Anyway, hope this helps
Dave
Vancouver, BC (Agriculture Canada Zone 9)