Killing bitkeeper history

Hi,
     We are using bitkeeper to manage a huge set of tarballs
(actually its the compiled results of an entire distribution;
lfs style); we are using this repo to represent the latest
version of our third-party distribution (i.e. all the the OS
and third-party libraries required in this embedded system).

The problem is, obviously, running expensive bitkeeper commands
on huge repos: takes too long even on fast harddrives and lots
of ram, I think I've even recently seen a `bk pull' fail to complete
due to an OOM condition.

What I'd like to do; to make it a little more practicle; is
to have a front-end repository that contains next to no history;
so that we can easily check out packages (as tarballs); modify
them and commit them; and every once and a while; completely
trash the history and; if possible; throw that history onto some
stack that we will never really need to touch unless something
goes terribly wrong ;-)

To put the question(s) in a one-liner form:
     - How can I remove all history from a repository ?
     - How can I conveniently pile changes from a stripped
       repository onto the "backup repo" ?


Cheers and TIA,
                              -Tristan

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