The Old Switcharoo

I have a class that has a lot of data members. On top of that I have a
lot methods that I dynamically mixin to that class as needed, and they
of course use those data members. The thing is the methods and data
members are numerous enough and related in such a way that there is
some contention for namespace. Since I'm only calling on the methods as
needed it would be cool if I could acually mix one in, invoke it, and
then snatch it back out just before executation begins to let the data
member back in. In other words, I guess I want caller context sensitive
(cflow?) namespacing.

Interesting? Possible? Any clever ways to pull it off in pure Ruby?