Actually, Zheng Tan had smelled that uncomfortable odor as soon as he entered, slightly stronger than the one in Boss Cai's rest room, and the source of the smell was the highly tense cleaner. Looking at the cleaner's nails, Zheng Tan wasn't sure if this great aunt knew she was in a very dangerous situation.
Apart from cleaning tools, the restaurant issued uniforms and shoes to all cleaners, so those who were working would leave their own clothes in the locker, from which Zheng Tan could smell an even stronger odor. Of course, it was only relatively stronger and might not be discernible by human sense of smell.
Zheng Tan couldn't possibly explain all these details to Boss Cai but by now, Boss Cai had realized there might be something wrong with the bottle of cleaner, so he had quickly taken action.
