I have. Also asked my LC friend about it. It is not necessary, Kellymom says that, too. BUT it is okay, if the mother is more comfortable with it, which I am. There is always spare BM in the fridge and I researched the peak times and when alcohol is out of the system again. I know it is silly, but am just happier with that. I pump 6oz in 10 minutes, so it is not too much work.
But I agree, I don't HAVE to do that.