How to reset Rails.cache servers? Rails.cache.reset is undefinied

I'm trying to get memcached working for my rails app that's running
under passenger. Apparently we need to check if passenger forked
memcached, and if so we need to establish a new connection using a
reset function.

I've seen people install cache_fu and they're able to call
CACHE.reset. But for the built in memcache-client in Rails 2.x
there's no such Rails.cache.reset.

What is the equivalent to this? Do I need to install cache_fu?

everything works great on my dev machine with memcached running with