When I was working at a veterinarian office we induced vomiting with Peroxide mixed with water for dogs that had very recently eaten something potentially harmful, especially if it was an older dog and we didn't want to have to knock them out to do the whole charcoal thing and/or draining the stomach. We also told folks to use peroxide mixed with water based on dog weight if they called in a panic before bringing them in.
I'm glad your pup is ok, sounds like you were very worried and very prepared. I know we had lots of folks worried about chocolate.. it is poisonous to dogs but it seems every dog is different, some end up being just fine with a little bit or a very large amount and some get sick from the smallest amount. I've never heard anything about salt but they told me at the vets that grape seeds were also poisonous. I never knew that. I think a lot of these things are more 'potentially poisonous' so better to be safe than sorry and just skip them all together.
I worked at a grocery store when I was like 19, this old lady came in every day, tied her dog outside and always bought a chocolate ice cream sandwich with her groceries which she gave to the dog upon leaving..

? I told her it was poisonous but she was just an oblivious old lady

Can we see a picture of your dog??

- Sarah