In article ,
Jeff Liebermann wrote:

On Fri, 16 Mar 2012 11:56:04 -0700, (Dave Platt)
wrote:

Possibly dunking it in a large ultrasonic-cleaner tank would help?
The scrubbing cavitation bubbles might be able to release the hardened
good from the surface texture.

Good idea. The cavitation under the rubber might help break it loose.
I don't have anything big enough, but know where I can borrow one (the
local electroplating shop). Hopefully, it's high enough in frequency
to produce sufficiently small soap bubbles.

Somehow, that reminded me of the time one of the programmers took
advantage of his ability to get into the building on weekends to de-gunk
his motorcycle engine in the vapor-phase board cleaner at Pertec, lo
those many years ago.

The manufacturing folks never found out who did the deed, but they sure
wanted to ...

Isaac