Starting with version 1.7, the strip command allows you to specify multiple sets of changes for markup and allows you to use revsets. So
$ hg strip "outgoing() and not author('Brandon Leiran')"
will delete all changes in one team. In other words, you do not need to search for the base (s) yourself, the strip will process it for you.
However, if you want the databases to be used in some other context, use the roots
function to calculate them:
$ hg log -r "roots(outgoing() and not author('Brandon Leiran'))"
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