There is a json file with the containers, I also had a similar problem (temporary containers extension “leaked” containers and they got synced) but after having

There is a json file with the containers, I also had a similar problem (temporary containers extension “leaked” containers and they got synced) but after having found that file (I believe it was containers.json or something similar) and manually removing from that all the bad elements I managed to get those out from syncing it to new instances.