Regarding RO desalinators

I've recently acquired an early model desalinator (can't afford a new one) and have a couple of questions which are not in the pdf manual I downloaded. Can anyone help?

1. What is so special about the oil used in the high pressure pump? There are numerous oils on the market for compressors at under $10/quart. What's so special about the manufacturer's brand of oil at more than double that price (plus shipping)?

2. When cleaning the system, the manual recommends an acid wash and an alkaline wash. Again, these can be purchased from the manufacturer, but when on the high seas, it would be nice to know there was a generic alternative. Anyone have a recipe?

3. Am I right that when pickling a desalinator for an extended period of time, I should use food grade propylene glycol with no alcohol content?

4. Is there a membrane supplier in the Pacific NW who has competitive prices?

Thanks for any input. Rick

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.