I thought I'd give this stuff a try, so I got a package from Amazon.
I'd read various reviews, but here is my take so far.
I built some nuc boxes and used the Ecowood on two of them. The stuff is literally water thin. I had the stuff everywhere. After I coated my boxes and waited several hours, there was only a very slight bit of grey color to the boxes. So I coated them again. A little darker but not much. I could however tell a difference the second time I coated them. They seemed more waterproof, if that's the correct way of describing it. While I did that, I had a shim/beetle baffle made from cedar. Wow did it really turn grey and after just one coat.
I had a scrap piece of birch furniture grade plywood and I dipped it into my Ecowood bucket. Today I looked at it and it too had taken on a nice grey color.
( I got the grey instead of the brown but would expect similar results)
I did read something about using this stuff on pine and how it didn't color very well. It's true, it doesn't. But I have to believe even without a lot of color, the stuff is still penetrating the wood and leaving behind whatever it is that protects the wood.
Obviously I plan to weather test these before using it on my hives. I may use it on a few honey supers, just to use it up.
I will make some out of pine and cedar to test how it does this year.
I would be curious to hear anyone else's personal experience with Ecowood.