Repeated experiments showed that after opening, metal particles are present on the inner walls of the oil filter. It is worth noting that on engines with small runs of iron mud, the filters may not appear at all, even under the influence of a strong magnet. From this we can conclude that life hack with magnets is suitable for motors with medium and large mileage.
Buying a neodymium magnet in our time is not difficult, you can buy in the online store or order from AliExpress. For an oily filter, cheap small magnets are suitable. As practice has shown, for this purpose, a pair of pieces installed on the bottom of the filter element is enough.