A rude equivalent to a "TV box" term

Solution 1:

Idiot box or goggle box.

Both terms have been around since the fifties.

idiot and goggle box

Alternatively, brain rotter is nicely descriptive.

Solution 2:

Boob tube is the way to go:

boob tube, noun. Etymology: boob + tube (television); from the notion that television programming is foolish or is viewed by foolish people : TELEVISION ; especially : a television set

Boob tube also enjoys wider currency than idiot box, at least according to this Ngram:

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Solution 3:

I rather like "glass teat", although it's not as popular as the others.

Solution 4:

The opium of the people? ;)