Zom-B-Gone is a clear glass bottle filled with blue fluorescent fluid. It has a makeshift label wrapped around it that reads "Zom-B-Clean", while the crafting station itself reads "Zom-B-Gone."
When thrown, it creates an area that keeps zombies from entering it for a small period of time. This is especially useful in small areas, as it can efficiently block off an entire hallway, and is a good replacement for the Gas Grenade, as it gives enough space to revive a fallen teammate without worrying about killing zombies.
The table to place the tiles is located in front of the Bombstoppers Perk Machine.
There are multiple locations that the tiles could spawn, and all are going to be in the nearby vicinity so its an easy one to get pretty early on while only requiring a small handful of doors.
One of the first locations is inside Heebie Geebies. Go through the doorway directly across from the Black Cat Dojo and directly to the left, right before you go up the stairs, there will be a small red table. The tile spawns here most of the time.
The second location for the tile to spawn is right outside Heebie Geebies, on top of a stack of wooden pallets next to a window. If you head down the alleyway and take a right just before the car, the pallets will be in the corner with the tile sitting on top. The tile generally spawns here more often than not.
The third location will be right next to the buildable table itself. If you are looking at the table, turn slightly to the right. At the foot of the chainlink fence in the corner near the table, where it meets the brick wall, the tile will be sitting on the ground. This spot appears to always spawn a tile, so its a good place to start.
A fourth location the tile could spawn will be directly up the stairs heading into Disco Inferno on one of the tables.