Off-topic:
Thom and Alan, LOL, I'm nowhere near as clever as Thom has pegged me to be.
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On-topic:
Yep, it's pretty much anything goes -- and honestly, IMHO, I do see it as being "hey, if it works for you, then it's all good!"
Go to a car-show or a local sanctioned (or unsanctioned, LOL!) racing event, and you'll literally hear 100 different opinions on lubes of various types if you ask 100 gearheads for their thoughts.
Aside from manufacturer's recommendations, it's pretty much really just "do whatever works for you."
Here in Ohio, for example, my car pretty much requires two different types of transmission oil, winter and summer. The winter mix makes the tranny feel kinda sluggish in the summer, but get the summer lube in the winter, and I'm always grinding the first-to-second upshift.....my car just seems to be temperature sensitive.
As you get to know your knives more intimately, you'll figure out what they like and what they don't, and you'll also figure out what your preferences might be in the trade-offs between attracting dust/dirt, rust-prevention, lubricity/viscosity, etc. that phatch so wisely mentioned above.
With high-dollar customs, I'd still definitely recommend that you contact your knifemaker, if at all possible. They may well have very specific reasons for choosing or even avoiding certain lubricants/solvents.
Allen
aka DumboRAT