You can't do this if you use any dynamic T-SQL. Dynamic T-SQL won't show up in any investigation of object dependencies.
Instead, you can use the DMV sys.dm_db_index_usage_stats to find what objects haven't been referenced by any queries. Here's a query I did on SQLServerPedia for that:
http://sqlserverpedia.com/wiki/Find_Indexes_Not_In_Use
The query is designed for performance tuning indexes, so you'll need to tweak a few lines. Here's the modified query:
SELECT o.name , indexname=i.name , i.index_id , reads=user_seeks + user_scans + user_lookups , writes = user_updates , rows = (SELECT SUM(p.rows) FROM sys.partitions p WHERE p.index_id = s.index_id AND s.object_id = p.object_id) , CASE WHEN s.user_updates < 1 THEN 100 ELSE 1.00 * (s.user_seeks + s.user_scans + s.user_lookups) / s.user_updates END AS reads_per_write , 'DROP INDEX ' + QUOTENAME(i.name) + ' ON ' + QUOTENAME(c.name) + '.' + QUOTENAME(OBJECT_NAME(s.object_id)) as 'drop statement' FROM sys.dm_db_index_usage_stats s INNER JOIN sys.indexes i ON i.index_id = s.index_id AND s.object_id = i.object_id INNER JOIN sys.objects o on s.object_id = o.object_id INNER JOIN sys.schemas c on o.schema_id = c.schema_id WHERE OBJECTPROPERTY(s.object_id,'IsUserTable') = 1 AND s.database_id = DB_ID() ORDER BY reads
Keep in mind that this catches all indexes, and you'll need to sift through - some of your objects may be heaps, some may have clustered indexes, etc. I'll leave this as a wiki so someone more ambitious than me can edit it to build a deduped list. :-D