I've been doing my nails with Shellac at home for two months now. The reason? Because the last time I went to a salon the nail tech insisted on taking a drill to my nails. They are wrecked.
When I took off my Shellac today I found that my nails are almost halfway grown out from that salon visit.
For those who think "Well, you have to let them take off the top layer so it will adhere.. " that is complete and utter BS. I buff my nails before applying Shellac, it adheres fine and stays as long as I don't pick at it, even with playing my ukulele pretty vigorously. And as you can see, the bit I buffed is still healthy, while the bit they took the drill to is just destroyed.
Moral? Stick to your guns on refusing the drill. I was trying way too hard to be polite (I even tipped him!) and now will still have months and months of growing out to deal with.