Lie like a pig in mud

I used the phrase "a pig knows the mud he rolls in" to mean that someone knows the familiar territory among his peers, the other day. My wife thought it was a crude phrase and objected to it.

Are there phrases that mean the same thing, but are more genteel? What I wanted to convey is that a person who long works in a particular field knows his peers and their habits and intents, knows the work, knows the routines, understands the signals, etc.

Thanks.

Never heard that one, although I don't understand you're wife's interpretation.

Simply that pigs are gross and dirty to some people and not to be spoken about among city people.

The meaning to me seems harmless and just as you say. But an old favourite of mine involving pigs & mud, is to tell someone who is clearly telling you a great porky is to say that he is "lying like a pig in mud".

Or another one is to be as "happy as a pig in mud". So it appears to me that pigs in mud are of great importance in one form or another.