/ Cleaning your Hydraulic Connections/Connectors #11
I use brake cleaner also, for most hygiene requirements where petroleum products are concerned. Unlike carb cleaner and such, most types don't attack most painted surfaces. Air or a rag cleanup.
The easiest solution is to change them out for flat faced skid steer couplings which are easily cleaned with your hand or a dry rag.
I like WD40, its a great cleaner. I'm always concerned that Brake Clean or other harsh cleaners/solvents will damage the o-rings-probably unfounded though.