I live in a 1963 houes with 4 stacks and each with a clean out. The prior owner obviously never used the clean outs because they have 3 layers of paint on them. I am unable to open any of the clean outs and I have two drains that will not empty on the first floor. Any trick besides brunt force to open these. They ate cast iron pipe with a brass bolt plate. There is dried plumbers cement in the grooves.
Any help would be appreciated.