i don't know how widespread full support for nip-09 is but #realy - the one i am building does

what you need first is to get the complete list of all the event associated with the account, so you probably need to write a spider that scans all of the relays to compile the list, and then break it up into reasonable numbers of events per delete event and then broadcast those everywhere

relays that support it some of them are even configured to propagate events to other relays to make it actually happen