A friend of mine does this full time. He has several techs. I believe this is the system he uses. The cheap kit you get at lowes doesn't come close to this one. These rods clip together. The ones that screw together can come apart if you accidentally reverse the drill.https://www.abatement.com/dryer-vent-cleaning-system.html
I used to do cleaning, luckily I am busy enough now that we don't. A lot of the houses here have this goofy newer style cap that gets clogged with lint so you either have to go on the roof or through the attic to clean it.
Not to mention that lots of people have the booster fans in the attic that need to be cleaned and serviced.
Its a good business for him.
It is not cheap. I think it runs about $400 or so for the kit, but he says its worth it.