The Sanitizer API is still under heavy development. We do not recommend relying on the polyfill for stability and can not fully promise the same security guarantees as the finished API will.
The polyfill might provide a shim on top of DOMPurify, that mainly rewrites the specified configuration object into a DOMPurify configuration.
DOMPurify is more interesting than other libraries, as it relies on the current browser's HTML parsing behavior (it is built on top of the NodeIterator interface).
There's a Demo page that loads all of the polyfill scripts and then does nothing. By default, the polyfill will bail out if you already have a Sanitizer object defined. But that can be easily overridden by clicking the ¶.
It might useful to test Element.setHTML