fling in
To throw or toss something into something else. A noun or pronoun can be used between "fling" and "in." Hey, open that drawer and fling these paper clips in, will you? I'm trying to clear off this table.
fling something in(to) something
and fling something into throw something into something. I will fling this thing in the trash. It is junk! Liz opened the laundry chute and flung in her clothes. She flung them in.