Setting up pbuilder or sbuild like experimental buildds

[Loïc Minier <lool+debian@via.ecp.fr>]

        Hi there,

 I'd like to setup a pbuilder or sbuild (preferably pbuilder, but I'm
 not sure it's possible) in the way I understand experimental buildds
 are setup: to only pull experimental software when it's required by the
 build-deps, but keep only unstable software when possible.  I would
 also like experimental software purged after builds of course.

 Would someone share an APT + pbuilder / sbuild config to achieve this?

   Thanks,
-- 
Loïc Minier <lool@dooz.org>