Hi. I live in an apartment that's 30 years old. The toilet flushes slowly because of blocked rim holes, but the manager hasn't done anything about it. With the economy the way it is, the management company has bigger problems than my toilet. I saved all the letters I've been written as proof of their nonresponse and I'm willing to fix it myself. Looking under the rim of the toilet, 17 of the 21 rim holes are blocked. I've tried to open them with a bent coat hanger but they seem to angle sharply toward the front of the bowl. I've read that you can pour muriatic acid down the overflow pipe to clear them, but would someone please explain clearly how to do that? Do I block all the holes with something to hold back the acid while it clears all the debris? How long do I let it sit? How much do I use? Luckily this bathroom has both a window and a fan, so I can get good ventilation going.