Yup. I refused a few because of their attitude. I let them know that I'm just doing it mostly for fun and to stay active. They can takes their attitudes + money somewhere else.I used to do that to until a brake job turned into me being the cause of a lower balljoint failure a month later. There was no way of convincing him that it doesn't work that way. Family I still take care of, friends and neighbors must participate and get dirty.
Edit: And factory parts only unless the owner aware of the risk.