Are you mostly worried about how to make the electrical connection? Pogo pins are very reliable even in gunky situations. We used them for all the charging connections on our old rugged devices. Put the male end facing up (So liquid can drain down into a pocket below) and the other surface can be flat so it’s easy to wipe clean.
Blade connectors are also useful in that they self wipe, but they’ll be harder to clean around and will collect visible gunk even if it doesn’t impact the electrical contact.
As long as the mechanical base can be keyed so it can only go in one way.