Thanks for the info, Texas_Ranger. If you have never been to Brazil, you would probably be shocked (no pun intended) at their electrical code. While the country is finally bringing things up to North American standards, it is going to be decades before those standards are common in most existing homes. Grounded outlets are just becoming mandatory in new construction, for example. Homes don't have central water heaters like in the U.S., so showers are equipped with electric heated shower heads. These are powered by (often ungrounded) 220 volt leads coming right out of the wall above the showerhead. There are no GFCIs used anywhere either. Outlets are often located right above sinks, and kitchen sinks often have 220v "water heaters" on them as well.

A good solution that I thought of might be to bring along a plug-in GFCI to use with the device.