I´m mainly using CLOU oils (don´t know if they´re distributing their oils outside of Germany?!). The oil i used on this project is called "Clou Hartöl - rotbraun"; but I also use other finishes like laquer, danish oil, shellac,...
Regarding the knife block: There are 6 smaller magnets in the block, so that the block carries 6 knifes. I think one big magnet would be very expensive and perhaps there could be some kind of disturbances when placing knifes on both sides of the block ???