This thread sparked a question in my head. Imagine that you are in a situation where you need to dispose of you wallet seed backup, but it is etched on a steel plate - how would you do it? The easiest answer is likely acid, but not everyone has access to it, and depending on the steel plate, it might be even highly resistant to corrosion. Another option is to damage it mechanically - in many of these steel plate products you are supposed to etch the words, so it should be possible to erase them or render unrecognizable. But it's likely hard to do thoroughly and traces of the words could remain.
Any more ideas?
To damage it mechanically seems like the best choice, using acid which can melt your steel plate is probably a dangerous option for those that do not know what they are doing, and melting it with heat seems just as impractical as using acid.
However anyone should have around their home a way to damage that backup to the point no one could recover any information from it, the only issue is that this could take some time, and if you were in a hurry to destroy it you may not be able to do it in time.