Umbraco 7.3 I believe will introduce the ability to call:

ApplicationContext.Current.ApplicationCache.RuntimeCache.ClearCacheObjectTypes<IDictionaryItem>();

So you may find this will begin to work in the accompanying version of Courier.

In the meantime If you create a new dictionary item on the target site, of any content, it will break the entire dictionary item cache, and your new items will appear, without performing an app pool recycle.

With the 'cloud umbraco cache refresh' project I do this workaround/hack in code:

 private void RefreshDictionaryCache(Guid publishId )
        {
            //currently the hashtable that contains the cache of dictionary items in memory
            // only gets cleared when new items are added or removed
            // there isn't the function to clear the cache
            // this is coming in 7.3
           //ApplicationContext.Current.ApplicationCache.RuntimeCache.ClearCacheObjectTypes<IDictionaryItem>();
          // so it would be a horrible hack here to temporarily create / update an existing DictionaryItem called "TempRefreshCache"...
            // .... apologies
            var ls = ApplicationContext.Current.Services.LocalizationService;
            if (!ls.DictionaryItemExists("TempRefreshCache"))
            {
                DictionaryItem newItem = new DictionaryItem("TempRefreshCache");
                foreach (var translation in newItem.Translations)
                {
                    translation.Value = publishId.ToString();
                }
                ls.Save(newItem);
            }
            else
            {
               var dicItem = ls.GetDictionaryItemByKey("TempRefreshCache");
                   foreach (var translation in dicItem.Translations)
                {
                    translation.Value = publishId.ToString();
                }
              ls.Save(dicItem);
            }

if that helps..

Thanks Marc, that is great. Thanks for taking the time to get back to me on this.

Jamie

is working on a reply...