"I like to use water (on his waterstone) because its foodsafe"
yes. similarly, i like using ketchup for this reason.
I also like how he "effortlessly pulls" during his tomato demo but when they cut to the close shot of it actually cutting you can see his index finger actively pushing on the spine.
haha. yes, effortlessly. you can see in the first shot he starts to draw it across the tomato, but it's just sliding around on there. then it goes to the closeup shot, and he's got his finger on top applying pressure to get it to cut.
link to the tomato scene