SORTED !
Those cheapy brush sets on display at various places, one steel, one brass the other nylon bristles - almost toothbrush shape Brumby

brand. I tend to buy them and put 'em away for days like today. Got them out. Googled to find there is an RTV silicone cleaner/remover stuff - in the US.
Not got the best working posture, kneeling on cardboard sheets but got stuck into them, two lefts, two rights and found the affordable Australian Export degreaser from say, supercheap, applied neat to this sili stuff sends it all gooey , soft.
Also used the cheap woolies green scouring pads, one per box, and kept up the tiny screwdriver in the grooves
It also disolves Mr Ansells cheap gloves very quickly, so my hands feel like erk at present.
Pulled the cams outta one set, also removing to clean the oil spray bar for the cams. Cleaned inside, outside, washed out and blow dried.
Next, for my spare set to put away.....
My machine shop guy reckons I need cast iron heads for the heat my LPG turbo combo is or was creating to blow my head gasket and ripple head face !