Do you have a source for this? My understanding is there is almost no tracking whatsoever of gold. Yes, if you brought in a new poured ingot, someone will want to confirm the purity, but there are no required identification stamps on gold that connect it with an owner (some gold dealer may add them voluntarily). Dealer will be happy to pay cash as long as they know they aren't get scammed.
My father in law buys gold coins all the time. They are all identical and there is no way to determine ownership. You can buy and sell in cash. No questions asked.
Now, if you went to gold dealer and tried to offload $1M worth of unmarked gold ingots, you're risking a call to the police who will ask you where it came from. But beyond that, it's a pretty unregulated market.