Can I use PieSync to clean my contacts too?

No, PieSync keeps your contacts in sync two-way and in real time. We use the email address as the identifier to determine if a contact needs to be matched and kept in sync between two applications.
PieSync will do everything it can in the back-end to avoid duplicates. Enabling the additional Avoid Duplicates functionality (only sync contacts with email), is an extra layer to protect you from duplicates.
However, syncing a messy database, will result in twice the mess to clean up. Always clean up your contacts PRIOR to the sync and make sure you have NO third-party or app-native integration enabled.
Here's are some tips and suggestions on how to clean up your databases PRIOR to the sync.