pete?

ok every time i clean my car i use simple green proffestional on my tires to get the tire shine off but even if i use a brush and scrub the hell out of um the shine never really comes off does anyone have any ideas on how to get it off without using somthing that will completly turn my tires brown? its so caked on there that when i put more on the mask the ugliness the old stuff that didnt come off just kinda absorbes the shine lol its pretty sad