How long does "seen before" last (or how does it work)? [Ditto block channel]

[J. P. Gilliver]

I often use the (tedious, five-click-with-movement) "I've seen this
video before" function.

I sometimes wonder if it has any effect at all; certainly it's not
permanent, which I suppose is fair enough - there might be cases where I
wouldn't mind seeing it again, after a decent interval.

Does anyone have any insight into how the function works? (Things like -
can you set the interval? Does using it repeatedly lengthen it? And so
on.)

I sometimes resort to "don't recommend channel", if it's one I don't
really mind not seeing recommendations from, and I _think_ that has a
longer effect. Anyone got any feel for whether that _is_ permanent, or
if not how long, and similar questions?
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

"Galbraith's Law of Human Nature: Faced with the choice between changing one's
mind and proving that there is no need to do so, almost everybody gets busy on
the proof." - John Kenneth Galbraith