Marinated Money Scam

A Vietnamese man in Norway lost around 35,000 dollars after he was led to believe that mixing the cash with a special liquid would double its value, Norwegian media reported Saturday...
The victim of the con, who was not identified, was reportedly told by the Frenchman to leave a mixture of real cash with blank bills to marinate in a special liquid overnight, and the next morning he would have double the amount of cash at his disposal.
But when he showed up the next morning to collect his prize, both the cash and the suspected con-artist, whose name was not revealed, had disappeared.

[Count Victor Lustig] became the leading practitioner of the so-called money-making machine. He told suckers he had invented a process that permitted him to feed plain paper into a machine and turn it into currency so perfect that no one could tell it from the real thing. There was good reason for this, since the "counterfeit" that spewed out of the contraption was real money. The success of the outrageous swindle was in its telling. Lustig sold the machine over and over again to such diverse characters as businessmen, bankers, gangsters, madams and even small-town lawmen.