Good point. Definitely something to be aware of before making such a choice. I would only do it if the clicker terrified my dog, and it does terrify some dogs.I wouldn't start useing a ballpoint pen. The meaning of the clickers is that after a click always comes a reward. This means that after every ballpoint pen click you as the trainer have to give a reward to the dog. Everytime someone in the house, train, shops, training area, in the car, visiting someone else, etc you have to remind this and give your dog a reward.
So try to found a sound less familiar. (that's also one off the reasons not to use a "good job" of "yes" as a marking point instead of a "click").
What you can do is buy a different clicker. There are some clickers on the marked who have 7 different clicker sounds (they say it somes in handy if you train different dogs).
Then you can sellect the sofftest one.
Now there are some electronic clickers, as you said. That might be a great option.