Minecraft – How to purge taint

They come from the leaves of silverwood trees, the same as any other tree. They are, however, extremely rare, so maybe expect one from a whole tree.

This is to balance the fact that plating one makes an Aura node near (or inside) the tree.

The way I always tackle this is with an advancing wall of fence posts. Assuming you have mine shafts nearby (since that is where these spawners usually show up) go grab a whole bunch of them.

Now, you are probably in a 3-by-3 shaft, so go to the wall of wood pillars and place a 3-by-3 wall of fence posts over it. Next, go to one of the side walls and break out the middle block (the one at head height) which is immediately adjacent to a fence post you just placed. This will make a gap on the side of the fence wall that is wide enough for you to mine away or place blocks behind the fence wall, but narrow enough that cave spiders can't fit through.

Beware, the spiders can still reach you to hit you if you are too near the gap, so maintain a safe distance and time your attacks when the spiders approach the gap. Once you clear enough of them out, you can walk up to the gap and start to place another 3-by-3 fence wall ahead of where the current one is. Then you can break the first fence wall and advance.

Lather, rinse, repeat and eventually you will get close enough to the spawner to either destroy it or place torches to deactivate it. It can take some time but it will keep you from getting killed under a tidal wave of angry poisonous spiders.