Can words just be words? That can be a tough question to answer. For the most part words do have power. They can insult or lift up another person. They can cause blame or forgiveness. Words do have some power. They have the power we assign to them.
In my home the only words that are not acceptable are insults. Any word that means something derogatory or is used as an insult is not part of our home and family culture. Beyond this, our children are allowed to speak any word or words they see fit. We do not use "potty words" often in front of the children, yet they are welcome to use such words in front of us.
We frequently discuss how other people see "potty words" or "curses" because in the real world not everyone is like us. Some people are very religious and some religious people look down on certain types of words. Some people are steeped in culture and think such words are "bad" or "dirty". We talk about job interviews and visits to the store. You just never know who you will offend and why. Until you know someone well, avoid "curse words" so as to not offend.
We also stress that the children not hide themselves. These words can be used to explain frustration or excitement. These words can place emphasis on a feeling that other, more commonly used words do not. If these words are something the children use to express themselves, so be it. As I mention above, the only real requirement is that we insult no one using such words and that we do not use words that are commonly used as insults even if that is not our intent in the word's usage.
You might think we swear all day long as do our children. It is rare that any of us use "swear words", even the kids. If something is not banned, humans are less likely to want to participate in that banned activity. Not only are we encompassing all non-insulting words, but we also are helping our children to develop their self-led inner compass. They are learning inner discipline, instead of peer pressure or fear based "discipline".