I personally have no problem using my safe word if it's needed. I would be afraid of loosing Master's trust if I didn't use it and I ended up really hurt. The entire reason I started this thread is because there are so many Doms who are new to the lifestyle and may not have been aware of this. Thank you all for your useful responses. If even one person learned something from all of you then I am a very happy person.

Anyone have any useful advice for Doms just starting out?