as discussed recently here[1], I hacked together a PoC to ban any unicode in URL's as an anti-phishing solution to mitigate homoglyph attacks. It works on Linux by hooking directly into the kernels NFQUEUE and processes any requests that are being sent to your local resolver (dnsmasq/unbound, etc) on port 53.
https://news.ycombinator.com/item?id=21824350