If you post a video, even without showing your face, your voice may be recognizable if one of your students or colleagues stumbles upon your videos.
The safest thing to do would be to post on a blog under a pseudonym.
You've tagged your question with "ethics", but your question is not about ethics. It's about how you can "share your knowledge" without getting caught. As for the ethics of PUA (i.e., manipulating people for sex), I'll just say that enough people would consider that unethical that you're right to be concerned about your reputation and career.
Edit: OP, I owe you an apology for implying that you were trying to be manipulative. According to your own answer to this question, what you are trying to offer is more along the lines of advice on how to overcome nervousness when speaking to women. You also say that you are not a native English speaker, which I suspect is why you do not recognize the negative connotations of the term "PUA". This has a very specific meaning--the use of body language/charisma/perceived status as a means to manipulate a woman into sleeping with you. It sounds like the term "dating advice" would be better suited to what you're trying to share. Depending on the content of your videos, I believe you may be able to openly maintain a video series on dating advice without risk to your career. For more information on the connotations of "PUA" vs "dating advice", I suggest making a post in the English StackExchange (https://english.stackexchange.com/).