I dunno - I don't do much of anything to my 3 disc brake bikes. Road, CX, MTB - squealing isn't really an issue. Wet conditions will cause noise, but all the other times they are quiet.

No special cleaning... about once a year or so I may sand the pads and rotors down a bit. Nor do I really "bed" them in properly. I do hear other bikes that sound like an angry goose - not sure how or why.