First post here. Old house. Cast iron pipes. I want to remove the clean-out plugs before I need to clean out the drains. Found two clean-outs. One outside, brass plug. One inside under bathroom sink, plastic plug, 3". Both are stuck. Soaking with Krol and PB Blaster. Inside one is not a problem. Comon size and plastic. Don't see a problem getting it out. Outside one looks to be brass. 3" plug is to big. I measure it as 2 1/2". Can't find one anywhere. I don't want to break it out untill I find a replacement. I've soaked the plug with Krol, PB Blaster, and heated it up with a propane torch. No luck. Any suggestions?????