If I were the man running WGT, I would sell "Random Exchange Rate Vouchers" in the pro shop.
In other words, this is a voucher which gives you the right to exchange (convert) a certain amount of your silver coins to gold credits at a randomly set exchange rate.
Obviously, most of times, you will get a crappy exchange rate like 1:100,000 for instance, but there are also 1:1(!!!), 1:10, 1:100 and so on to lure the players. And there should be also a limit of amount, for example, you will be only able to exchange no more than one million coins at a time per voucher.
The voucher price? Well, you set it in consideration of how much the return rate* would be. I'm sure you have experts for that in the company like most casinos do. ;) (* You guys call it RTP, return to player, right?)
If WGT makes this come true, it would sell like hot cakes, flying off the shelf.