Old guys at lumber yards are a gold mine for tips, but calling it a card scraper is a bit off. That's the flat piece of steel you use with your thumbs. He probably meant a cabinet scraper, the kind with a handle and a blade you can adjust. Both are great for tricky grain, but the cabinet scraper is a lot easier on your hands for a big job.
Fellow old-timers also say to grind the burr on them scrapers with a good burnisher, not just push it around. That burnisher work makes a huge difference in how the scraper cuts. They also like a light touch with some oil on the wood to keep the shavings from clogging. Saves a lot of sanding on curly maple for sure.