https://en.wikipedia.org/wiki/Reco-reco The presenter was wrong to try to translate it into English. You couldn't find 'reckons reckons' - or anything like it - because the term doesn't exist. We apparently call it a 'reco-reco' in English, just as you do in Portuguese.

1) This instrument doesn't exist in the United States, so we would call it by its untranslated name, reco-reco. 2) Certain kinds and styles of music, originating in the common people, such as "jug band music," use a similar kind of rhythm produced on a "washboard." Washboards were actually used for scrubbing clothes clean, but became repurposed into improvised instruments. I would never call a reco-reco "a washboard." I might describe one by saying "a reco-reco--a Brazilian folk instrument that sounds like a washboard." https://youtu.be/D4BcfkKLgpY?t=7

Thank you, Blair!

Thank you very much Blair!

From my initial probing online it looks like the English term for it is just a straight use of 'Reco Reco'. Because it has such a cultural origin it would work perfectly without a translation. I suppose it would be like asking 'What's the English word for Caravel? ... or Bossa Nova? ... or Fado?' Hope that helps :)