I have had to have my sewer line snaked out six times in the last seven years. The line is approx 30 years old. The town put a camera through the line and there was alot of soap and old grease build up. The sewer line is like a clogged artery and over the course of 6 months to a year it may become blocked again.
I have spoken to plumbers and they are not aware of any products that will clear my sewer line.
A construction worker i had spoken to while visiting a plumbing supply store suggested using muratic acid. He had used it on his line and it worked well.