The trace breaking potion, and unregistered (and therefore easily discardable) wands were the only ideas he had had, and even he had to admit they were weak ones. Harry was right when he’d derided the hour the potion would give them - that was barely any time at all. Not for this. And the wands only true value was affording them anonymity - at least they wouldn’t have to worry about their own wands incriminating them. And both of those things were useless if they didn’t think of some way they could disappear and not be missed, something that was unlikely considering how closely watched they were.