where was the smoke alarm made?
A lot depends on the type of extinguisher you used. That you have a residue indicates that you used a dry chemical agent. (carbon dioxide, halon or other clean agents don't leave a telltale residue.) The first thing is to determine what type of agent was used. If the powder residue appears white in color, you most likely used a BC rated extinguisher charged with Sodium Bicarbonate. In this case vacuum out as much excess powder as you can. Wipe the remaining down with a damp cloth or sponge. For anything that appears baked on, you may need to use a nylon scouring pad like you would use on teflon coated pans. Be careful not to use too much elbow grease because you don't want to scratch the surface of the oven. If the agent appears to be yellow in color, you most likely used an ABC rated extinguisher. This will be more difficult. The nature of ABC chemcial is such, that once heated to about 350 degrees, the agent is designed to soften so that it adheres to vertical surfaces. As it cools, it hardens making removal very difficult. Additionally, heat alters the chemical to the point that it becomes very corrosive to metals, electronics, etc. I would try the same procedures I listed above but, you'll have to thoroughly remove all of the agent as water also causes it to become corrosive. Follow each wipe down with the damp sponge with a thorough wipe down using a clean, dry cloth. Do not try to heat the oven until all agent is removed. And, do not use any type of chemical oven cleaner as the reaction could be very dangerous. Cleaning this way may or may not work. Your oven might be a goner.
I would use regular dish soap and water with a lot of paper towels. I'd be afraid of mixing any other type of chemical with it just in case it interacts. You might just use hot water to clean it.
It stands out from other things to a dog, if you are walking along a pathway and their are sevral trees that look the same and a fire hydrant that is most likely closer to the sidewalk all it takes is one dog peeing on it to get it to be a popular spot to pee on. Once one dog marks it the rest will follow. If I want my dog to potty quickly I find a spot another dog peed on and let her smell it, she almost always goes in the same spot.
Moving a fire hydrant is a very complicated, very EXPENSIVE proposition. You'd have to petition the city council to get it moved and you'd have to have one heck of a good reason building a ramp for a physically disabled person may be good enough, but if it's more for personal convenience you can forget it. You can also expect the city to be reluctant if there is another solution that doesn't involve moving the hydrant. But hey, you don't know until you try, so call the city and start off with the Department of Public Works. If they don't handle it, they can tell you who does.