All the ballast in those photos is dug up from outdoors somewhere. The top photo features mostly material a friend acquired near a river in Oregon, with some additional sand that I found on a parking lot adjacent to a beach in northern California. The second yard is two different colors of sand I found next to a road in southern Idaho.
The effect seen in the photos is no more than a combination of the different sand colors, plus weathering applied with acrylics and chalk dust after the ballast is glued down. I use prototype photos extensively, as well as observations from railfanning, to get a feel for how track looks.
I use the inexpensive simple gray variety, non scented. I have 900 ft of HO and 350 ft of O scale track painted rail brown. Most of it has been there for more than two decades. None of it is glued down making modifications to track work as simple as vacuuming the desired area and make the change,paint, and ballast. In my opinion the desired effect is achieved at a reasonable cost. I have over 100 Atlas turnouts on the HO layout with no issues. The O scale layout is entirely Gargraves flex track and switches,again no problems for decades. The layout is built in the second floor of a custom built oversize two car garage Which is kept extremely clean with it’s own furnace. As a side note…the HO layout is Model Power code 100 flex track with Atlas turnouts…all brass and in service for nearly 30 years with no problems. The HO layout is on the top level and the O scale on the bottom level. In summation…my experience has been favorable, spend your money on a good quality locomotive.
It very probably is illegal on Staten Island based on some research I did. I think the NYPD has better things to worry about then a guy removing a pound of sand but I guess illegal is illegal.
I model in G scale and use as kitty litter for ballast on 3 layout’s. In HO I would think it would be applicable for boulders and large excavation material. It stained mine by simply emersing it in a water bath with acrylic paint added then sun dried it and glueing was identical to regular ballast. ONLY use the clay non clumping type, traditional Johnny Cat is best, just pick out the scent crystals unless you want blue rocks in your construction site.