Good for your dad! I'm sure that I'm older than he, but we old fart's can learn a new trick here or there! I think that there may be some differences between the son and father shaves.
1. As you stated in the original post/your are simply removing 'peach fuzz'!
2. Your father has a lifetime of much heavier growth to try to remove!
3. I'm wondering if your father has done the research that you did? Perhaps 'you' can show him where you learned what you have! I'm going to be 59 in less than a month and all of my children come up things that I learn from!
4. With the above said, I enjoy learning from my children/it's kind of 'What goes round, comes round'!
Good Job Dad!
Thanks for the words of encouragement! As said before, I'll try it again!