Lots of comments on here - different products, some do damage, some not.
I was just trying to tell you all about one that works well. When we used it, the TC shined like new, so I don't think it did any damage. And, I'd be more careful than that.
So, it's a good product, works easily and the bugs vanish. Doesn't appear to do anything to the TC sidewalls, in fact makes them look like brand new. Just sayin' M44
Chlorox cleaner w/ bleach. I believe the 'bleach' part is a very slight mix in it -