How many layers should one get for a Jessner's Peel?

I had a Jessner's peel that did virtually nothing and caused no peeling, and then I have had Jessner's peels that caused me to to peel a ton of skin for many days! The estheticians who applied these peels never discussed the number of layers they applied, but I am assuming that was the difference hat caused the peeling and lack thereof. What is the appropriate number of layers one should get applied so that the peel has good results but doesn't damage the skin?