I had a couple pairs of silk boxers when I was in my 20s. Comfortable and slightly erotic feeling, yes. Practical, NO. I did not like the whole hand washing in the bathroom sink. Eventually the seams busted out, and I didn't buy any more.
A younger friend of mine who lived with me for a while wore silk boxer shorts exclusively, so I decided to give them a try. They were very soft and lovely to feel on your balls but I was getting too frequent erections from them. They also didn't last very long, seams opening up and other fabric flaws. I went back to cotton boxer shorts.