You mention the dreaded poisson chat, are there crays as well?
Drilled Soaked wooden balls in glug.
Hard hookers, I make up a 1egg mix of my normal base mix with around 10% of extra egg albumen, and 50ml of glycerol. The flavours are usually what is required to a standard 6 egg mix.
Boil, and then air dry, give a roll in glycerine, then dry again until rock hard. You can each time you roll in glycerine add a few drops of flavour.
It may still be worth meshing your hookbaits though.
My 1 egg mix makes me enough (pop-ups) for a years fishing, so will give you plenty for a French trip.