Cache sometimes is not being updated on saving operations
Try Expire module  instead you try to clear cache manually.


  This module provides configurable actions upon events that will expire
  URLs from caches like reverse proxy caches, internal page caches,
  etc.This module make more sense when Minimum Cache Lifetime setting is
  set to a value other than none.
  
  There is now integration with the following modules:

Boost - deletes expired pages (files) from the file system.
Varnish - integrates over an administrative socket.
Fastly - Varnish/CDN caching
Purge - expires urls by sending purge requests to Varnish, Squid and Nginx over HTTP.
Acquia Purge - allows Drupal sites hosted on Acquia Cloud to automatically purge pages from their Varnish powered load balancers..
Memcache Storage - allows to delete pages that were cached in a memcached instances.
Akamai - provides an integration with the Akamai Cache Control Utility (CCU) Web Service
Recacher - Page cache warmer.



and Memchache Storage mdoule 

Features

This module is an alternative to Memcache API and Integration module focused on different set of features. Available features (D7):

    You can move all cache to the memory.
    You can move users' sessions to the memory.
    You can move lock system to the memory.
    Module can store cached pages for anonymous users as a plain text, so proxy servers (like Nginx with enabled ngx_http_memcached) can get such pages directly from memcached pool and avoid heavy requests to the backend.
    You can clear data from single cache bin, cache cluster or flush all cached data from Drupal UI (screenshot).
    You can find helpful nice debug output (screenshot).
    Integration with Drush
    Integration with Administration menu. Module provides link for flushing memcached data from navigation toolbar.
    Active development and support.