Some areas have all night supermarkets and some stores will carry herbs, and they might have charcoal. I had to use some when my girl ate some of the plant I was trimming and she started frothing at the nouth - I used 8 capsules for my 18 pounder. Luckily the plant wa only mildly toxic.
Burnt toast I sometimes used as a substitute, but I don't think it will be potent enough, and it might have to be given sooner, closer to ingestion.
I hope thing will be okay, keeping you guys in my thoughts.