I think it would be unwise to write a tutorial on how to retrieve the data on those disks. I'm not even a computer expert but i managed to find retrieval software on a HP support site...
Ofc its wise. It should be common knowledge that you can not trust these printers. If only a few know about these vulnerabilities the majority will not be aware of the risks and the few knowledgeable can exploit that. Btw you can print an encrypted paperwallet that is useless witout a code that will not be printed. E.g. Mycelium wallet backup uses this to backup the private key(s).