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Answering your question as written, this is a hardware-specific question. Since solid-state storage chips typically keep the details of which cells are being used to write data hidden from the OS, never mind the user, in order to be sure you've erased any unit of data beyond recovery, your hardware vendor would need to have written that functionality into its drivers somehow, and then you'd need a way to access it, from Linux. And you would need to trust that your hardware vendor is both competent at this task (which is rarely verified by consumers, after all) and uncompromised by the threats you're concerned about.

In my experience, the best approach is to encrypt a solid state device before ever using it, and store the key, or a passphrase used to decrypt the key, on a device from which it is more difficult to recover. Wetware works well.