Galvanized steel - that means they will be corroded by any solution containing any dissolved salt, even just kitchen salt. Corrosion is an effect of presence of water and air oxygen, ions present in water just lower water resistance, making corrosion faster. Corrosion is an electrochemical process - that means something gets reduced, something gets oxidized at the same time. Reduction consumes electrons, oxidation produces them - for both reactions to take place at the same time charge has to flow from one place to another, the lower the resistance, the easier it is for the charge to flow, the faster the corrosion. Obviously what you learned as an electrician helps to understand what is happening here
Brushing whatever is there is a good idea - otherwise you risk fast corrosion in future. You can't do anything about future leaks, but the solid present is to some extent hygroscopic - it will get water from the air moisture, water+salt gives the same solution that speed up corrosion previously.
Respirator - the simplest one should do, as I told you earlier you are not dealing with anything toxic, so it is just to prevent breathing dust in general. In case your skin gets irritated simply washing it with water should help.
Note, just in case: no guarantee that the information given is reliable, I am honest and doing my best, but I can be wrong.
Some more information about both sodium acetate and sodium bicarbonate:
http://www.jtbaker.com/msds/englishhtml/s2666.htmhttp://www.jtbaker.com/msds/englishhtml/s2954.htm