Heavy Firescale

Any suggestions for removing heavy firescale from sterling items
with finely detailed design…that were in a house fire. This
firescale is unlike any that I’ve ever encountered. Mechanical
cleaning too tedious for the volume of material involved (not
that I’m lazy…) …commercial electrostripping is a
possibility, but I’d rather find another way.
Anybody out there with a helpful idea ?
Thanks
Ruth

Have numerous pieces of sterling with intricate raised design
which were in a house fire. Firescale like I’ve never seen
before! Any suggestions for removal of firescale while retaining
fine detail will be gratefully accepted. Thanks. Ruth