If you want to completely remove commits from history, you can also do a dump of the repo at a specific revision, then import that dump. Specifically:
svnrdump dump -r 1:<rev> <url> > filename.dump
The svnrdump command performs the same function as svnadmin dump but works on a remote repo.
Next just import the dump file into your repo of choice. This was tested to worked well on Beanstalk.