I'm usually very bad at dyno so I'm so happy to top this one! My trick was to keep both feet on the lower rock, it's easier to push when i jump up forward
Rain sucks, but broken holds suck even more. Remember, never climb on wet rock in Fontainebleau.
The sandstone becomes brittle, and pulling on it will ruin classic problems. Drying it doesn't help, because it's still wet and weak inside.
All you can do is wait for better conditions.