I'd say it's pretty risky either way, but you could insulate yourself from risk somewhat by using a raspberry pi with a fresh image on the SD card each time. A

I'd say it's pretty risky either way, but you could insulate yourself from risk somewhat by using a raspberry pi with a fresh image on the SD card each time. Also, if it's possible to run a raspberry pi from a write-protected SD card (and assuming that SD-card write-protection hardware switches are actual hardware disables not something that just sets a flag that the software can ignore), then you may not need to clean the SD card every time either.