Yea, every pot in Jerusalem and in Judah shall be holiness unto the LORD of hosts: and all they that sacrifice shall come and take of them, and seethe therein: and in that day there shall be no more the Canaanite in the house of the LORD of hosts.
Zechariah 14:19 This shall be the punishment of Egypt, and the punishment of all nations that come not up to keep the feast of tabernacles.
Zechariah 14:20 In that day shall there be upon the bells of the horses, HOLINESS UNTO THE LORD; and the pots in the LORD’s house shall be like the bowls before the altar.
Zechariah 14:21 Yea, every pot in Jerusalem and in Judah shall be holiness unto the LORD of hosts: and all they that sacrifice shall come and take of them, and seethe therein: and in that day there shall be no more the Canaanite in the house of the LORD of hosts.
The verse centers on "jerusalem", "judah", "shall", "holiness", "lord", "hosts", and "sacrifice". It is saying that the verse draws attention to "jerusalem" and "judah", so its meaning should be read from those terms before moving to application.
The prior verse says "In that day shall there be upon...", giving immediate footing for "jerusalem" and "judah". In Zechariah context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "jerusalem" and "judah" with trust shaped by these words, not by a vague optimism outside the passage.