as a foreigner, that sounds weird and possible to have double meaning... I would rather use bathroom then... But as my Russian teacher have told me a few days ago (after I've taken this exercise), Russian houses have the toilet room separated from the bath/shower room. I guess that's the reason why Russians would ask specifically for the toilet.
Edit: I have lived in Ireland for half a year and it seems that that issue with the word toilet is exclusive to the USA. I've only seen "restroom" as the name for the toilet in US American restaurants there like Fridays and McDonalds, but the normal places would use "toilet"
The Russian word туалет, just like the English word, come directly from the French word, but that's about the only similarity. It has nothing to do with whether the "toilet" (hygienic device) is collocated with the restroom or not. In English you can also ask for the "toilet", or the restroom or the bathroom or the WC/water closet >_>.
In Brazil there is the word "toalete", also (I say in Brazil because I don't really know about the other Portuguese speaking countries). But it's not common to be used. Sounds too posh for us. One would only use it in an expensive restaurant when you get a bit embarrassed of asking for the bathroom.
Usually we would use the word "banheiro", which means "the place where you bath" or "the place that has a bathtub inside" (the act of taking a shower/bath = banho | bathtub = banheira)
While at it, I've just realised that "banho" sounds a lot like "баня" (banho is pronounced like "банё")
What about lavatory? It's a common-though kinda formal-saying too. When restroom is accepted, maybe it should be too.