Since its introduction in 2009, application of the rehydroxylation (RHX) technique for dating fired-clay ceramics has been controversial, with very few satisfactory dating results collected in the interim. The stability and efficiency of this technique has been called into question by several investigators in the last few years, who have struggled to reproduce and validate this new dating method. Based on our new mass gain measurements for ca. 2000–7000 yrs old ceramic artifacts, the reproducibility in the RHX process rate is analyzed and discussed. Timespan analysis was performed, and age uncertainty related to RHX dating technique was evaluated by considering the error propagation. The results show poor reproducibility of the RHX process in the samples of the same origins, which give new evidence for a revision of the RHX protocols.