Boeing4Ever - Having been subject to the spray myself (and including being in the LH MD11 that arrives in akl) i would harldy call it an enduring event
As other have pointed out most a/c that reguarly visit NZ have a residual spray certificate which LH are not prepared to fork out the $$$ for.
It seems to be more the biz jets and GA types that get the manual spray down and wait is only 5mins before the doors/holds can be reopen. Others can show thier empties which are supposed to sprayed at TOD i believe (bit hard to do this on an MD11 with only 2 crew and however many holds etc to get done at TOD)