The copper will certainly slow the disease but I would use the diluted bleach spray and not just hit the plants but everything in the greenhouse to kill all the spores that must be everywhere in there. After using the diluted bleach spray I would come back the next day and apply a copper spray for prevention. I don't know what quality of bleach is available in your country so it may be difficult to find something suitable but read the thread below and see what you think. I fight gray mold every single year because I love to grow black tomatoes and they are highly susceptible to it and it can spread fast here where our climate is so so humid. Good luck.
http://tomatoville.com/showthread.ph...t=bleach+spray
Bill