I do believe that a host is obligated to disclose their location OOCly if they choose the IC-hunt option. It's basic RP etiquette to have your current location known, because otherwise, anybody could say that they're suddenly in this or that certain place. It really should be something that should cause a host to be stripped if they can never be tracked down or reached at all. As a host, you are committing yourself to spur on RP activity, not prevent it.
There are very few places that are only reachable by very specific methods, such as Kamui's Dimension or the Moon. But we have plenty of Kamui users, and I can just blow up the moon anytime. Custom time-spaces can be an issue here if a host chooses to dwell there all the time.
As for the hunter's perspective, you should have sensible ways to track down a host if you really do plan to go after one of these pure beasts of chakra. Regular chakra sensing can suffice. Using Sage Mode's passive chakra-sensing abilities can really help too. Mind's Eye of the Kagura is the best technique to use though. Doujutsu can help too, especially the Byakugan. But remember, ultimately you gotta be ninja about it. Hunting a Tailed Beast is the ultimate test of all your ninja abilities.