I don't know the price of the chains and sprockets - it's down time that is priced where industrial lubricants are used. I could offer you industrial lubricants and a choice of application methods but the MOQ would undo it. Your options though, would be....
One way to go is to immerse the chain in a quality gear oil that has the ability to penetrate the pin bush areas of the chain, is tenacious so won't fling out, is water resistant so wont wash out and has a load bearing capacity that actually keeps the wear surfaces apart.
Another option is to apply via aerosol either an oil or grease with the above properties which has a solvent carrier to bring the lube to the pin bush area.
In ether method the start point is a clean chain. Once the lubricant is applied the internals of the chain stay clean the oil/grease stay in place excluding water and debris. The lubricants I'm referring to were developed in and for drag line mining - it doesn't get more arduous than that. I have customers running chains under water (dredging filth) and the chain survives.
However I'm not going down that route. Instead, have a look at the link below for Cool Run chain lube. I've seen that run on karts - where when it's dry its dusty and when it rains the chains get soaked - with good results. Circa £8/can the last I heard - worth a shot. A clean chain is the start point though. Once a chain is contaminated internally, unless it's washed in solvent it's trashed - which is why using lubes that keep the water and dirt out are essential.
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