I have 2 sets of nice and firm chain tensioners (<86 or Carrera) and am wondering if I can take them apart for a nice internal cleaning. They are grimey on the outside and suspect a bit of crud inside. I have a nice ultrasonic cleaner to stick them in. Any advise on cleaning these. Should I stick them in assembled and blow them out or take them apart? Are they more prone to failure

if taken apart?
Mike