How is "Palaki au i lo'u lauoho i kēlā i kēia lā" not correct here? "i kēlā i kēia lā" is also translated as "every day", and is done so by other translations here in duolingo.
I feel your pain. DL is defining kēlā i kēia lā as "each day" or "daily."
"Every" is defined by DL as i nā lā a pau.
a pau = all, entirely
How is kahi i ko'u lauoho wrong? Kahi can also mean comb, and can be used in many, many, different situations... "Palaki" is just the hawaiianization of 'brush'