Anyone understand DAT machines??? (Tech question)

I've successfully used cotton swabs to clean VHS heads, but I didn't rub the swab across the gaps. I just gently dabbed 99% isopropyl on them gently several times. DAT heads seem like they'd be even more delicate, so I'm not sure I'd even do that.
Cotton swabs are definitely forbidden with rotating heads. You must have been extremely lucky to get away with it. Sam's business card idea is safer if you don't have the right type of swab.