I work with multiple projects, and I want to recursively delete all folders with the name \'bin\' or \'obj\' that way I am sure that all projects will rebuild everything (so
On our build server, we explicitly delete the bin and obj directories, via nant scripts.
Each project build script is responsible for it's output/temp directories. Works nicely that way. So when we change a project and add a new one, we base the script off a working script, and you notice the delete stage and take care of it.
If you doing it on you logic development machine, I'd stick to clean via Visual Studio as others have mentioned.