[Other] Trouble Editing Item Text in Bag

[Aduel6]

I tried using two tools: Item Manager and Complete Item Editor to edit the text in my Fire Red ROM for Oak's Parcel when you choose said item,. Instead of it saying "OAK: {player} This isn't the time to use that!" I want it to say "OAK: This isn't yours to use!". But it seems that this is hardcoded. I looked and the routine offset is 0xA2239, which is "Do nothing", hence the Oak text. But I tried repointing the routine using shiny Quagsire's disassembly in hex to free space and change the text pointer to a custom one with the text I wanted and changing the 4 byte pointer accordingly with no luck (it freezes). I assume repointing on GBA games are different than most systems since I can't even find a list of opcodes anywhere in hex. So...what should I try? I would like to get this custom text for that item.

SERIOUS answers only, please.