I use the Doctor's Woodshop oil, in part because he is from Oregon. I slop it on first coat, let sit over night, apply another coat, kind of slop it on, then wipe it off. I did pretty much the same thing with Mike Mahoney's oil. For end grain cutting boards, more so than flat grain cutting boards, final coat goes on with a heat gun for better and deeper penetration. I don't buff my bowls out at all since that shine is gone the first time the bowl or plate is used.
robo hippy
I'm a fan of Doctor's Woodshop walnut oil. Its very clear, very nearly colorless stuff. I used Mahoney's in my first year, but once I found the Dr's Woodshop stuff, I noticed how much the browner-colored Mahoney's was coloring my wood. Dr's Woodshop stuff is not entirely neutral or clear, but it hardly adds any color at all. As with any wood, there is that normal "darkening" (which, IMO, is a misnomer...its more a change in how the wood disperses light than a darkening IMHO), but there is very little change in color. So, a hard mapler or holly or other very light colored wood, will generally maintain its color. In contrast, linseed, tung, and mohoneys' always introduced some notable color shifts. Linseed is the worst, and the color can change over time. Tung isn't too bad, and I actually prefer its slightly warmer tone to the yellow of linseed. Mahoney's is the least of the three, but still notably more than Dr's Woodshop.
@Alan Weinberg
Something I did learn about walnut oil. If its purified, it has no proteins, and will NEVER go rancid. Ever. It also oxidizes at a much slower rate, so it doesn't go bad in the bottle nearly as fast, but, it also takes a lot longer to polymerize in the wood too. Its not a so-called "drying" oil, so it won't cure as hard as Danish or other drying oils with metallic or other drying agents, so it doesn't really protect the wood. It makes it look nice, but its not exactly protectant. It does seem to wear out over time, dull over time, so pieces need re-finishing over time as well. Further, I have never read anything or seen anything about walnut oil ever spontaneously catching fire. It oxidizes more slowly, and while I won't say that its impossible, the risk is significantly lower than with say linseed oil or even more so the drying oils or anything with accelerated oxidation time. So there are some benefits to walnut oil, but overall its not the highest quality finish IMO.
If you want something durable, urethanes or varnishes will usually be better. Hardwax oils might be better. Drying oils will polymerize more over any given timeframe and provide a bit more durable a finish.
You mentioned Tung oil as the initial coat(s). One thing that is distinctly different between walnut oil and tung, is that tung can actually produce very water resistant finishes. It's been used for thousands of years in traditional crafts that need water proofing. If whatever you are finishing needs that, then switching to walnut oil won't produce the same result. I did not know this myself until earlier this year. I don't make many items for actual utensil use (such as bowls or platters) because I didn't think there were many truly "food safe" (i.e. free of VoCs, heavy metal driers, etc.) finishes that were durable. But I had a chat with someone on a pen turning forum earlier this year, and he gave me the lowdown on tung, and its great stuff for durable and water resilient finishes for utensil items. For that, I'd stick with pure tung oil, and not mix with walnut oil as the latter just isn't as resilient.
