Soft-soap is defined as insincere flattery or praise used to manipulate or persuade someone. Antonyms for this word would be straightforward, honest communication, and criticism. Instead of soft-soaping someone, speaking directly and honestly to them about your thoughts, feelings, or intentions would be the opposite. Additionally, instead of praising or flattering someone in a manipulative way, providing constructive criticism or feedback would be a more genuine approach. In essence, antonyms for soft-soap would be any form of communication that does not involve manipulation, flattery, or insincerity.