How LTM reports disable state to GTM

I'm not convinced there's a 'good' way to drain connections to a GTM balanced site. The disconnect beween client and server (i.e. the http connections come from client, but the DNS requests come via the clients LDNS) mean there's no real way to tie the two together.

So stopping NEW entries coming into persistence cache is easy. But for EXISTING ones,m it'll prove to be difficult, ESPECIALLY if you have a lot of clients from the same LDNS servers (i.e. Get enough clients on the same LDNS and you won't ever flush the persistence entry, so you'll never get rid of the clients hitting that site).