Replacing ferrofluid in B&W tweeters (old CDM series)

Does anyone have experience with this, cleaning out the old sticky ferrofluid and replacing it?
I’ve read some info on the internet and wonder why it seems so simple to do. There must be a catch somewhere.

Anyone know where to order ferrofluid in CH/ EU?

Yep i did some years ago, in a pair of B&W P5’s. Like you I was a little apprehensive but I didn’t have any issues.

Cheers Matt

P5 has the same tweeter.
Meanwhile I managed to clean out the sticky stuff, the magnets are now clean.
Ferro Fluid (original) should arrive tomorrow, it was ordered from
They also explain the process on their website.

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It worked, night and day difference!
Just to be clear, you seem to get the lower of the tweeter assigned frequencies back, the highest still worked with a clotted magnet.