castor oil packs, question ?

Hi all,

I am going to be doing the Caster oil packs on my knees and was wondering how many times a day and for how long should they be left on. I have some kind of deposits inside my knee joint that grind and is really loud when I walk.It doesn't hurt but they will some times swell if I have had to walk a lot or climb stairs. I think the packs will help to remove the toxins and help the joints recoop.

I have read a lot of post but haven't seen one reguarding the duration they should be left on.

Many thanks, Jenn