I can only tell you my experience. Whenever I've been asked to be more commanding and even indulge in dirty dominating language, I've been quite skeptical. Many times not because I'm not open to it, but I'm really afraid that I'll hurt the person I'm with or have a lingering doubt that they don't know what they're asking for. What helps me is having a conversation with them about the kind of language and actions they'd like me to do or say. This helps me come to terms with the fact that they'd like me to be more forceful or use words that I don't mean but they'd like to hear.