Blanch ⅔ of the lemons in boiling water for 5 minutes then drain.
When cool enough to handle, cut each into 8 wedges and remove the seeds.
Toss with the salt and pack into the jar.
Squeeze enough juice from the remaining lemons to cover those in the jar. Close the jar and keep at room temperature for 5 days – shaking gently once per day.
After 5 days, add the oil and place in the refrigerator.