Larry,
Welcome to the forum community.
A single low branch is more easily air layered instead of stooling. Any of the documented fig "air layering" procedures will work better because a single container will be used to contain the new roots of the air layer and it can be removed well before the end of the season.
Stooling works quite well with fig trees because multiple shoots are produced at the lower nodes when the apical tips are pruned, but the stooling process is a bit more involved and is better suited to propagation of multiple plants like the mentioned apple rootstock... A single trunk with a substancial root mass is cut close to the soil line, similar to pruning in a bush form, the soil is then mounded as the multiple shoots grow out, when the plant is dormant, at the end of the season, the individual rooted branches are seperated and grown as individual trees.
Good Luck.
BTW, Stooling is a form of Layering, as is Air Layering and Ground Layering.
Stooling just requires additional planning, pruning and a longer period of time to harvest new individual plants.
