I think I was able to use rm -r, but in some cases event that might not work. This Mac OS X hints discussion has several fixes: Script to delete huge sparsebundle images.
- AppleScript invocation of rm -rv
- unix commands including use of bands, xargs, head, find and so on.
The article includes related references
- osx - OS X - argument list too long for rm -rf *, 4000 files - Super User
- Perl to the rescue: case study of deleting a large directory | Randal L. Schwartz [blogs.perl.org] (millions of files to delete - some good discussion there too)