Here's a stainless steel conical filter designed for your Chemex brewer. This is the new generation Kone made by Able (Coava Coffee).

This is a true conical shape - not like a #4 filter that is a cone with a flat bottom.   So you can also use it with other brewers that take  cone-shaped filters, like the Hario V-60,  but it may not fit as perfectly as it does in the Chemex.  It works in all sizes of the Chemex that take the square filter squares.  It does a fair job of mimicking the extraction of a paper filter and eliminates having to throw away a filter after every brew. Be sure to wash it out after brewing since the holes are very tiny and will tend to hold onto coffee after you are done.  It is easy to keep clean with a general purpose coffee cleaner - the same type you would use to clean a brewer or thermal carafe.

The Kone is the co-star of one of our brewer comparison videos. Click here to watch.