Translation of "철저히" in English

CBP에게 몇 시간 동안 철저히 무시당한 후,

After several hours of being stonewalled by CBP,

아니면 머리를 철저히 멀리하고 꼬리를 잡는 방법입니다

Or, I'll try and grab the tail, stay away from the head completely.

제초제는 일절 사용하지 않으면서 철저히 효율적인 방법으로

I began to see it as oddly, almost perfectly natural

‎생존법을 가르쳐 줄 ‎부모도 없어요, 철저히 혼자죠

She's got no mother or father to teach her anything. She's alone.