It may sound like an old method, but I find it unique and effective.

  "  Inside the box is a small wooden box (which needs to be opened with a small key)
with a thin glass bottle and thin paper wrapped around the bottle,
which is written on it "Bitcoin BTC Seed. "

That means:
If you try to open or break the wooden box without the key, the glass bottle inside will break and acid will come out and destroy the paper writing, so there will be no chance of theft!!!  I thought that instead of acid, using lemon juice and light pen writing would be much safer.

                 (If you don't have a hardware wallet, you can think about it.)