I love to build, but when I'm starting, sometimes my starter homes are dirt, just to be "safe" through the night. (I hate dirt towers, so I'm making a hut right away!) I know a lot of admins hate when players make dirt huts, but we all start somewhere. Anyways, once I have some wood to build with, I can craft the replacer (most of the time, unless the materials to make them are modified by world owners). Then I begin to replace all the dirt I can with the wood, even if it's not the same type, just to make the house "not dirt". I have even used wood to make fence windows until I have a furnace and glass. (You do what you have to do to survive!) The replacer just saves me the time of digging or chopping down the original house and lets me replace one node for whatever other node I have in my inventory that I want to use.
How to use the node replacer(explaination is for pc users only; mobile users, sorry I have no way to explain the process):
Set out one of the nodes you want to use for the replacement node (ie - stone block).
Using your replacer, click on the item by holding shift and right clicking.
Once your new node is selected, pick up the node you placed out of your inventory so you are able to use it.
Click on the node(s) you want to replace.
**Note:** This only works if you have the new node(s) in your inventory. If you only have 1, you can only place 1, unless you have creative.