Magnetic diff bungs

[castellan]

I am just thinking if i could get a magnetic diff bung.
When someone has a LSD diff. what i have found is the metal pollutes the oil very fast even at 20.000 KM it looks bad . but i have seen open wheelers that the oil looks like new at 90.000KM.

So i was just thinking if anyone makes a magnetic bung.

Would it be best to have one on the oil filler or down at the drain?

Changing the oil cost a fair bit now days with the additive. i think i could lengthen the change interval with one.

What do you recon.