Would there be any benefit in using foreign key words in the code of a website when trying to get more hits in a certain country?
I know having a separate site in the native language would be ideal, but is there any benefit with just using the key words of specific terms?
If you mean within the keywords meta tag, then no, because none of the major search engines pays any attention to that when ranking your site, and as far as I know, any that bother with it at all do at least check that the keywords in your meta tag actually exist on your page.
Even if it worked, would it really help you? Somebody types a keyword in their own language, then finds themselves at a site written in English, which perhaps they don't speak. All that will do is increase your bounce rate.