If you are just going to use the plumbers sink tape to punch through sludge you might try heavy duty wire of similar 1/4" width. The "ribs" on the wire could help remove gunk and it will be more flexible. I have NOT tried this but I think I am headed for a PCV clean on my 2001 V70XC P...

Location? Price? Any other details. What trip and city mileage can I expect?