A topic almost as common as cleaning agents for circular saw blades?
Almost any non-drying fluid will serve as a honing fluid, although on smooth-ish stones (some natural stones for example) a lubricant is a positive disadvantage. The function of a lubricant is to separate two surfaces, the opposite of what you want when abrading.
I've briefly tried all of these on a fine Aloxite oilstone. (But recently moved over to a diamond plate).
Neatsfoot oil, I used it for many years.
Cycle oil or "3 in 1" oil
Thinned down engine oil
Redex petrol additive
Glycerine thinned with methylated spirit (3 to 1). Recipe gleaned from a nineteenth century book.
Brake fluid. I've been using it for several years now without any evident ill-effects, but my exposure is not very great.
Sperm, olive and sweet oils are given as serviceable.
Soap has been recommended for the purpose [of facilitating honing]. The stone is wetted and rubbed with soap and more water is applied until a lather forms. This is allowed to dry, and when the stone is required for use it is merely necessary to wet it slightly. ..."
Almost any fluid you can think of that is non-drying, not too viscous. It should be able to float away the metal particles and thus prevent them being embedded in the surface of the stone.
I suspect that some of the special honing oils sold to woodworkers in small quantities/high price are engineer's honing fluids intended to be used in copious quantities on precision grinding machines.
Linseed oil. It is a drying oil and will form a skin.