Patience, patience. You can safety-proof the doors one at a time!
When it comes to this cat, I have all the patience in the world, as I’ve said before. With all the abuse he took as a feral and the stress he was under at the sanctuary, I’m not going to try and force him into doing anything.
I worry about the chemicals, but he’ll come out, sooner or later and the doors can be locked then. Eventually....