Which way is most efficient? Say you bought dwarf hairgrass, do you pull out every single little strand and place it into the gravel?
What do you do with your new plant?
Hairgrass, I'll unpot and plant every freakin' strand. If they're larger, more manageable stems, I'll take a bit of lead tape and put a bit around each stem individually and plant them that way.
I will remove the plant(s) from the pot, take off as much of the rock wool as possible, trim the roots if necessary and then put the plant(s) in the substrate. When I got some dwarf hairgrass a month or so ago it took me almost an hour to do this and separate out the plantlets and put them around the tank. It worked though because the dwarf hairgrass has spread like crazy.
I separate the plant(s) from whatever shipping material they came in. I rinse all of the plants very well, removing any bad leaves or stems in the process. The plants get a soak in a potassium permanganate bath and then another rinse-off before getting planted.