I tried to clean my old neodymium magnets, both from Gamma and Beta, and succeeded, but thay lost too much of their body mass and pull. Out of four EMIMs two are gone. Today received new neodymium magnets from China, bought on ebay, for peanuts. They fit right in, are only about .1 - .2 mm thicker and .2 - .3 mm wider. I put them on (not glued yet) to check the pull and it is very, very similar to my good undamaged half. I figured if my speakers played ok with magnets half-gone, they should play much better with these. I may put a thin paper spacer or two just even out the pull. I also plan to buy a whole bunch of these magnets for spares.