Most of what are called "silver casino tokens" don't contain any silver. There were some early $5 tokens that were silver and over the intervening years, several casino have issued high-face silver tokens, usually $25 and $100 denominations. Most of those have already disappeared from use due to the introduction of bill changers and ticket out hardware. There is silver in some of the premium tokens that fall out of (but cannot be played in) slot machines. These are worth at least $10 in redemption value and silver content is much less than that.

In summary, there are essentially no more silver gaming tokens for people to redeem or sell for bullion.