(someone) could sell ice to Eskimos phrase informal
Someone is such a smooth or convincing salesperson that they can sell things to people who don't need or use it.
The salesman was a real fast talker, and somehow managed to convince me to buy an extra car. He could sell ice to Eskimos.
A problem or difficult circumstance
I'm short-sighted, so forgetting my glasses is a real hair in the butter for my sight.