First off I fit kitchens for a living and there's nowt wrong with solid wood if it treated properly.
Worktop Express are excellent, product comes well packaged and protected.
I've use all the Danish oil and Tung oil products and they are hopeless unless you want to keep retreating all the time. They do not remain impervious to water and they take ages to dry leaving you with a useless worktop for several hours at least, every time you do it and the amount of dust which stick to it in that time is extremely annoys if you are looking for a quality finish.
I have walnut tops in my own kitchen and have found the best product for treating them is called e-z oil by a company called Morrells. It's about £13/litre, cheaper in 5 ltr cans.
You can apply several coats in a day and still use the top within a couple of hours of application. In fact it dries so fast that it's not a bad idea to "cut" it with some white spirit to give you a longer working time.
You can apply by rag or brush. I prefer the latter as I can get nice thick coats down which "flow" smooth. After a few coats you can if you wish get a glass like finish which looks great on a nicely patterned wood like walnut but may not e to everybody's taste.
By the way, do t forget to treat the underside of the wood well as you'll never treat it again in all probability.
Same goes for cut edges to cut outs for hobs and sinks etc.
Using this stuff I would have no problem with using wood for Belfast sinks etc and typically if you get enough on in the first place you'll only ever need to recoat if you damage the surface. Oh and it is certified for food prep areas.
Hope this helps