I agree with you. Then I suppose the weight, thickness and diameter mechanism was at work. I do not refer to the rest because I do not know the end. But I did tests. I took this coin of mine and others like it. I was doing the same with everyone, and ..? This particular one passed and the rest did not. The last time I checked it, as I wrote about 1.5 years ago. I've been to a large garden center and my few-year-old wallet has fallen apart. I pulled out everything and found this coin. Out of curiosity, I threw it into the machine and it works

The machine looked "modern" but I do not know if it was really.
And this is not a string method

and you didn't have to throw it in several times - this happened to me only 1 but it was my fault. But it is 100% effective (about 20-30 cans in total, various Pepsi and Cola machines).