dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(60 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
NSURLCache * cache = [NSURLCache sharedURLCache];
[cache removeAllCachedResponses];
[cache setDiskCapacity:0];
[cache setMemoryCapacity:0];
NSHTTPCookie * cookie;
NSHTTPCookieStorage * storage = [NSHTTPCookieStorage sharedHTTPCookieStorage];
for(cookie in [storage cookies]){
[storage deleteCookie:cookie];
}
});