What is the best method for cleaning flat face couplers prior to connecting? Is it wiping or spraying? If spraying, what type of spray product is best?

To clean flat face couplings, we recommend wiping the face of the male and female couplings with a clean rag. Compressed air also can be used to blow debris from this surfaces. We do not recommend using a spray cleaner (i.e. brake cleaner) as it is not always compatible with the valve seals. If a spray cleaner is used, avoid spraying directly on the valve seal and wipe excess cleaner off immediately. In corrosive or harsh environments, using a silicone based corrosion inhibitor/lubricant (such as fluid film or LPS-2) can help protect from corrosion.