Does running root killer down the sewer line help ?

[Gurjot Grewal]

I bought a long-distance SFH recently where the main sewer line(clay) had some signs of root penetration. It had been cleaned right before being listed on the market. The sewer scope showed some roots but overall looks pretty good. I read on the forum getting the tenant to run a root killer every 6months can help maintain the line. I brought this up to my contractor who works for my property manager and he believes that when clay tiles have been penetrated by roots it usually means the line will need to be jetted at least once a year. And did not think that running a root killer would help the situation. Is this something I should push for? Or is he right that it would just be a waste of time/effort.