to drown sb in a wicker basket, a form of 沉潭[chen2 tan2]
Definitions (CC-CANTO)
drowning of adulterers in a pig's cage as a punishment in the old days
Definitions (粵典–words.hk)
語句
古時中國嘅一種私刑，主要針對通姦男女，將犯人放入用竹造嘅豬籠，然後丟入河。輕則俾犯人頭部露出水面，浸若干時間；重則浸死 a lynching where adulterers are forced into a cage for pigs and thrown into water
Examples (粵典–words.hk)
Cantonese
以前淫荡嘅女人要浸猪笼。
以前淫蕩嘅女人要浸豬籠。
In the past, lascivious women were drowned to death.