tModLoader Item required in inventory to craft new items

[KrabTech]

I want a special item that wont be consumed in inventory to craft stuff. For example, a hand axe item that you need to craft wooden planks.
My current idea is to create a tile that cannot be placed then detect if the item is in inventory and use player.adjTile[<tile>] = true; according to this thread: Can you make an item count as a crafting station while in player's inventory?

So far, I don't know where this player update script is (ModSystem? ModItem?) and where to put it. I've used UpdateInventory() from ModItem but that only works for 1 tick.