Edding acrylic spray
Deep black, 200 ml
Edding acrylic spray
Deep black, 200 ml
Don't worry, I can assure you that most of the solvents evaporate after 30 minutes (most of them are ethyl acetate and acetone, so they are completely harmless in these quantities). The varnish also covers very well.
It probably does "work". The question is rather whether the leather is still breathable afterwards. In addition, it will probably flake off over time if the leather moves. I would rather use a black leather care stick from the shoe shop.