Book- Statuettes funéraires égyptiennes

The first question that an antique dealer or a young collector asks an expert in Egyptian funerary statuettes is: master, could you explain to me what the difference is between a chaouabti and a shabti? 
Personally, I would answer as simply as possible with an easy-to-remember explanation, and I would say that the funerary statuettes prior to the year 1000 BC. AD are chaouabtis until the day when the first prophet of Amon Pinedjem II, 
who organized the royal hiding place in Deir el-Bahari, imagined replacing the word chaouabti (in wood) by ouchebti (respondent), game 
A word that was so successful that all green earthenware, rarely blue, posterior to the Ethiopian period, from the Saite renewal, XXVI dynasty, engraved, with base and dorsal pillar, are still, without exception, uchebtis.