Pay to take it to the dump. Don't treat Goodwill like a dump and expect them to cull your trash.
Goodwill does provide a great deal of employment to people who are physically and mentally handicapped. It is likely asking too much to ask a mentally handicapped part-time employee to recognize your sensitive info and react accordingly.
You would not believe what people give to Goodwill, and yes, they use it as a dump.
My daughter works for Goodwill running the local “shopgoodwill.com” online auction, Goodwill’s answer to ebay. She has sold mink coats, diamond rings, and musical instruments worth thousands of dollars.