EcoTech replaced one of my MP40's wetside earlier this year. I just had to send them a copy of my sales receipt (I might've paid shipping both ways?) that I purchased in 2017. I never soak the magnets/props in citric acid or vinegar, just rinse and scrubbed under tap water. I had some extra cages that I would swap out for clean ones and soak the dirty ones in citric acid, but never the magnets. And still, mine rusted all on their own. But to your point/title of the thread, mine supplemented my iron dosing with a heavy dose of copper and RTN. Thanks Ecotech!