The manufacturers oil is somebody else's oil with the manufacturer's label. It is unlikely the pump is made by the assembler/marketer of the watermaker. Find the make and use their recommendations.
I found the best place to buy membranes is eBay or Amazon if it's a standard size.
Cleaning chemicals and oil can also be found on eBay or Amazon. Or buy them from a component system maker like CruiseRO.
Cruise RO Water & Power: Watermakers for Boats & Yachts
I liveaboard and use my watermaker year round. If you use the watermaker every few days in the PNW you don't need to pickle. Better if you flush the watermaker with fresh water. I flush mine with fresh every time. Mine is setup so I can flush the salt water pump, filters and membranes.
Membrane output ratings are based on 77°F incoming water. Cold water makes less water. I have a heater in front of my membranes and heat to above 70° for higher output in the PNW.
If you don't know, you can make water from fresh at reduced pressure. When cruising, I pull into fresh water where available and make water there and my engines get flushed, too.