If snow foam is a faff for you due to space etc, consider an all-purpose cleaner on the dirty bits (flies, up the sides and back) - but IMO you really need a pressure washer to minimise paint damage, a standard hose just doesn't cut it.

Exhaust pipes - try a metal polish, various ones out there but I like the Britemax twins. If that doesn't work, you may need to go with 0000 wire wool to get the worst of the stains off, then finish with the metal polish. But go as gentle as you can to start with, same concept as polishing paint - only go for a more aggressive approach if necessary