Drylok FTW! i love the stuff
Here are a few things i have discovered in my experience working with it. I find it easier to mix in acrylic paint to the drylok instead of concrete tints. Its also much cheaper, and you have many more colors to work with to give you the most natural color tone possible. I tend to break up the color of the overall piece as much as i can. Uniformity is not all that natural in rocks. What i usually do is start with a somewhat dark base tone, add random splotches of earthy colors, then paint all the cracks and crevices a very dark color to give it an added sense of depth. After that i use drybrushing to add even more depth and contrast with a lighter color on top.
Its also helpful to go out to a local creek or something and find some rocks you like to use as a very rough template for shape and color.
I don't use straight acrylic on my stuff now just because i find it looks kind of glossy. Mixing it into the drylok in small portions and painting with that takes care of the glossiness.
Another note: I tested the water running off drylok, and it had a pH increase of ~2.5 (i used RO water with a pH of 6, and it increased to 8.5), so i would recommend rinsing it thoroughly before adding inhabitants. I wouldn't call it necessary, it just helps.
I have not made a complete rock wall, but i have made some fake rocks. Here is my best one:
Great video by the way. very helpful and informative!