Translations and Searching

This is kind of a general question, so I think this is the place for it. We’ve tried several different possibilities for adding a language switcher (translator) to the site and being able to search in different languages. I believe most of the translators translate on the fly. So search does not work if you search [for example] a word in Russian. There are two plugins that allow you to manually enter the translated content (polylang & WPML). Polylang has glitches. Not to mention, I don’t think these will translate everything on the pages (just the content).

The other solution isn’t very viable since the site is built I don’t think… that would be Multisite. But I think that’s a ton of work just to be able to search your translations. Also, the owner doesn’t want to use Google Translate.

Is there any other solutions for this?

Thanks!