What you need to use depends on what is on there to get off. I usually start with something mild and progress until I get the results I need. Plain detergent is the first choice, but it won't remove most adhesives or old caulk. Isoproply Alcohol is great as long as the crud is soluble in alcohol, so that would be my second choice. Try it to see if it removes whatever is there. Mineral spirits is probably the 3rd choice and it works on most adhesives and caulks. Just don't slop it all over a rubber roof, cause it might also loosen the adhesive that bonds the EPDM to the substrate (EPDM is porous to mineral spirits). Use a damp rag instead. For the same reason, be cautious with the orange-type adhesive solvents (Goo Gone, etc) cause they too can go through the EPDM rubber and loosen the adhesives underneath.
Lacquer thinner, acetone and MEK are the solvents of last resort. They will remove most anything but are very likely to affect/damage anything else they touch as well. Not recommended unless you are (a) desperate and (b) have some experience with them. The proverbial advice "try first in an unobtrusive spot" applies.
