there is no way to empty the virus vault,
yes there is, but there is a bug in latest version, it give wrong message "do you want to restore" but file is deleted

see here >> https://forum.avast.com/index.php?topic=171152.msg1376184#msg1376184

Using the Virus Chest https://www.avast.com/en-eu/faq.php?article=AVKB21#artTitle

so yeah, 2 days ago, my computer started screaming at me DINGDINGDING THREAT HAS BEEN DETECTED!DINGDINGDING THREAT HAS BEEN DETECTED!DINGDINGDING THREAT HAS BEEN DETECTED!DINGDINGDING THREAT HAS BEEN DETECTED!.
do you want free help checking this here in the forum?