pompeyal - Sorry to read what a nightmare your bonnet mould has turned out to be.
Unfortunately, I don't have any experience of making "proper" moulds.
( So my use of parcel tape as a release agent is not relevant here. )
However,
Viatron posted on his build that he applied 4 coats of this release wax on his moulds.
( Apparently he has used it for years and it always works well. )
Obviously, not much help in this case, but make help if you have other stuff to make.
Good luck, Paul.