I believe that the silica gel practice came about as a result of VTTS failing to prevent corrosion on turbine discs by proper storage. RR's first reaction to the degree of corrosion was to scrap them. I think they did get around to some form of recovery eventually. While I wasn't involved, I believe RR was not too happy about the competence of VTTS which may have coloured their view of the change from Marshalls. I believe the CAA would have also had to approve the change to Cranfield; did they have any issues?
EAP
And common sense would have dictated the Silica Gel used should have been placed in the jet pipe NOT the intake. Sadly common sense seemed to be lacking, but hey ho, no use crying over spilt compressor blades.