Simple solution = Stop imports from China. There is so much of this on the market (see eBay) right now that I can't believe anyone would even think of buying these bars any longer, even if they were good.
Even if you stopped ALL imports from China, they would still come in, just through a second country. China to country X and then from X to here and they wouldn't be stopped because they weren't coming in from China.
A buddy of mine works for a company that rents parking. Among the recent receipts was an 1894-S "dollar" that is a Chinese fake. It's underweight and attracted by a magnet. Apparently, eBay, flea markets and such aren't the only places to find them.