Hi Aras,
 I went to a ship yard and tomorrow we will take down the fore stay, to be able to take it apart.
Like you I tried everything, rinsing with water, with dry lubricant, ... Nothing was successfull, it seems we have to take it apart and may be rebuild it by a machine shop.
 Regards,
Volker
 Mickmoon, Sharki, hull no. 176