Here is one way of doing so. The script bellow creates a script that deletes all orphaned users from each database. Notice that the script is using an undocumented procedure (sp_MSforeachdb) that could be modified in the future by Microsoft without any warning, so using it in a user application is something that you shouldn’t do (I only use it in some script that only me or another DBA is using). Also you should check the script that is created for other users that might have been created in the database, and that you don’t want to drop them.

exec sp_MSforeachdb 'use ?; select ''use ? '' + ''

go'' + ''

drop user '' + sdp.name from sys.database_principals sdp

left join sys.server_principals ssp on sdp.sid = ssp.sid

where ssp.sid is null and sdp.type in (''S'',''U'',''G'')

and sdp.name not in (''guest'', ''INFORMATION_SCHEMA'', ''sys'', ''BROKER_USER'', ''dbo'')'

Adi