Insane thing taught in a Polish school

I remember when I was in primary school and the teacher decided to do an "experiment". We had two jars, one with nice stuff written on it and one with swear words. we then out some food in them (I think it was bread with water). After some time, the jar with swear words had more mold and we were supposed to think that the words had some kind of magical powers. I just find it insane how can someone think that this would be a good idea. The message is not converted very well, but what is conveyed is a pretty big piece of pseudoscience, that many of the kids probably believed. I genuinely would not be surprised if some of my classmates believed it until this day.