It sounds as if his exposure was fairly limited which is good. I actually would have been surprised if he started to chew on it since these products aren't very tasty.
I'm happy to reassure you that in most cases, ingestion or exposure to these sorts of products will not be toxic....they can be irritants but nothing more. They might cause some gastric distress (vomiting or possibly diarrhea) but other than that, they aren't particularly harmful.
And, since so much time has passed and he's not drooling or vomiting, he's not likely to start.
The products which might cause significant damage would be those which have the word "danger"versus "caution" on the label. Drano or Clorox Ultra are two examples. If the label says caution, that means ingestion may cause mild gastrointestinal issues; however, if it says danger, it means it could corrode through your esophagus.
More than likely the label isn't attached to the product but it's not likely that it would have "danger" on the label anyway.
He should be just fine with no additional action necessary on your part.
I hope this helps to provide peace of mind. Deb