I just have them write the tools to write the DSL's to do the thing then (most of) the sloppy code stays in the generator and if all the different things depend on each other they don't go stale and whatnot. And let them design the DSL themselves for whatever task so it matches their 'internal concept' of how the things work.

Worked out pretty well so far but not really practical unless your goal is to make the tools to make the DSLs to make jitting VMs -- https://github.com/dan-eicher/BBQ kind of snowballed from "let's parse some binary files" to a way over the top toolkit for playing around with this stuff but, it's fun...