Good point! I hadn't considered that. Luckily, I sprayed outside. The risk of inhalation is probably minimal but not 0%. I'll be sure to wear a mask that can catch colloidal silver particles in the future.
All things considered, this technique should be used cautiously, though colloidal silver is low-to-moderately toxic (some people even consume it for "health"), it should be treated as a toxin.
Really great point ibe!