In article ,
says...
Question, do you think
heat would help free them??? If so would you heat the center piece or the
piece it screws into??? I don't know if they make those pieces any more to
dig out the packing and replace them. Most everything is plastic. I guess
you can figure out why I need to get to the clean out. If some one knows a
web site I would be happy to go there.
Sorry again for the off topic post.

Get a can of PB Blaster (penetrating release spray) and spray the thing
down and let it sit for a couple of hours. Add some heat to the outside,
the part the screw-in bit screws INTO, and TAP GENTLY to get more of the
blaster into the threads. Try wrenching it, reapply blaster as needed-
it might take three or four applications with heat and light tapping.

BTDT, worked to release the cleanouts in my 1920's house. Before
replacing the plug, coat the threads in wither teflon goop or use anit-
sieze compound.
good luck, hope this helps

--
Just some random guy,
Pull the _PLUG_ to email