Brake Clean could be iffy, test a place first.
Carb Cleaner is harsher, in my experience.
I usually use Simple Green, or Wax & Grease Remover on a rag, follow up with a dry rag.
Least invasive is glass cleaner or kitchen-use "surface cleaner", but they might smear as much as clean...

I once had a Diplomat that poured oil out of its oil pressure sender, hope you're "lucky" that way.
I have a BB with a similar but less-leakage symptom to yours, so I'm curious what you find.