Guangyun: xiāng yāo (xiang-yao) cut, Jiyun: sī yāo (si-yao) cut, pronounced xiāo (xiao - rising tone). Yùpiān (Yùpiān) explains it as boiling salt. Also, Jiyun has xiān miào (xian-miao) cut, pronounced xiào (xiao - falling tone). The meaning is the same.