In English we usually use tricks to count out seconds, like “Mississippi” or “Astronaut” or “Elephant”. Do Japanese people have their own ways of counting in their heads or out loud, and if so, what do they use?
And bonus question for non-native English speakers: Does your language have a way of counting? Because I’ve never heard of this being a thing outside of English.
Can’t’ speak for all French people, but it wasn’t really a thing where I lived.
The only time I encountered it was when passing my driver license (I was told to use ‘crocodile’ then).
As for Japanese, not a clue.
In German, when I want to count seconds in my head, apparently starting from 1 (“eins”) is too fast, but starting from 21 (“einundzwanzig”) does the trick. I think I also heard other people use this.
In elementary school in Norway I remeber being told to count one-one-thousand, two-one-thousand, three-one-thousand etc. For numbers with two syllables we’d drop the one from one thousand, and starting with 21 we’d count normally.
I usually count “a hundred and one, a hundred and two”.
When I’ve seen Japanese people doing longer, more deliberate counts, it tends to be something like this, where they lengthen the first part and punctuate the second. If it’s a one syllable one like に or ご, they still just make it work.
い～ち
に～い
さ～ん
し～い / よ～ん
ご～お
ろ～く
な～な / し～ち
は～ち
きゅ～う
じゅ～う
Maybe others have other ways, but this is what it seems to me.
That’s more a general “counting obviously” thing for playing hide-and-seek or whatever, no? This thread is more about ways to closely approximate the length of a second when counting in the head.
I used to do gymnastics, where you are supposed to keep strength and balance positions for (very very very loosely measured) 3 seconds.
I do remember a senpai saying "count like いちまんいち、いちまんに、いちまんさん“
But I have absolute no idea if it’s a Japanese thing, a Japanese gymnastics thing or a that-guy-on-my-team thing. I literally heard it from one person alone and that’s it. Please don’t go around saying Japanese people do that, lol
Right, and when I’ve had conversations about doing it in English they are usually perplexed and I’ve heard them offer this as the Japanese equivalent.
If someone knows a literal equivalent, it would be news to my wife.
I don’t see why something else would inherently be better, since there’s no science to it in the first place.
Same in Sweden, we count ettusen, tvåtusen, tretusen etc. which allows you to do proper counting and it’s slow enough for it to be roughly 1 second. 
One harakiri Two harakiri Three harakiri…
If you’ve watched Go matches there’s quite a bit of seconds counting, as they have time-keepers making sure each player make their move within a set time-limit.
Ichibyou, nibyou, sanbyou etc if said slowly and you don’t rush, is roughly 1 second long.
(Vaguely reminded here of an episode of Farscape where main character John Crichton has to teach D’argo (an alien) how to count up to 30 microts (alien time unit, approximately 1.3 seconds long) in his head. Crichton teaches him “one Mississippi, two Mississippi”, which he renders as “one… [annoyed glare]… mippippippi, two… [annoyed glare]… mippippippi” and I guess the annoyed glares took a third of a second each, because the timing wound up being spot on. But, it’s like, is there no situation on the other side of the galaxy where one might have to time something in one’s head? Did they just use computers for everything, or was there another species with a perfect sense of time?)
I completely forgot I even made this poll omg
Same in dutch.
For some reason I count ettusen-ett (one thousand one), ettusen-två (one thousand two), ettusen-tre (one thousand three); just adding the hyphen for easier reading, not used for numbers in Swedish. So I guess there is variety in Swedish too.
This sounds like an even surer way to make the counting take one second. I might change to your way of counting in the future! 
I’ve never timed it, but that was the version I learned to count for figuring out how far away a lightning strike hit.