Where there’s muck there’s brass
Definition 1 of 1
Pro Tip 1/3Regional Usage
Primarily used in the UK, so may not be understood everywhere. Recognize it's a regional phrase. 
When I mentioned 'where there's muck there's brass' in the US, they looked puzzled.
Pro Tip 2/3Metaphorical Sense
Often used metaphorically, not just about physical dirt or waste, but any messy situation. 
He started a software fix for a nasty code bug, sure that where there's muck there's brass.
Pro Tip 3/3Historical Roots
Originates from Yorkshire, where 'brass' means money. It's deeply rooted in British culture. 
Her grandfather often recited 'where there's muck there's brass' while polishing his old coins.