Can I create a rule with keywords contained in sites that can be blocked. I have users that still can access porn sites accidentally. Is it through third party advertising?
Modern search engines including Google, Bing, DuckDuckGo all operate on SSL-only connections, which encrypt traffic in transit (as it crosses the router).
adam:ONE lives on the router, so it has no man-in-the-middle (MITM) features and never will.
Therefore, keyword searches are not visible to a router function, and shouldn’t be, as it would be a privacy concern.
However, you should turn on SafeSearch for the above-mentioned search engines (the only three that offer DNS-based forced safe search), which will suppress all known porn sites in search results.