YOU SAID:

I saw my nan down an entire bottle in a swig

INTO JAPANESE

私はswigでボトル全体をダウンさせた

BACK INTO ENGLISH

I swig the whole bottle down with a swig

INTO JAPANESE

私は瓶で瓶全体を泳ぐ

BACK INTO ENGLISH

I swim the whole bottle with a bottle

INTO JAPANESE

私はボトルでボトル全体を泳ぐ

BACK INTO ENGLISH

I swim the whole bottle with a bottle