A castor oil pack gets the lymph system moving.  Many instructions tell you to use wool flannel, but cotton flannel works just fine.  Soaking a pad takes a bit of castor oil and some instructions tell you to throw the pad away after using it.  I don't do that.  I fold it up, put it in a zip lock bag, and put it in the refrigerator.  Then with each subsequent use, I add a little more castor oil.  The pad will last for six months or more this way, unless it becomes soiled.

Also, look into Essiac tea.  I have some on order from Mountain Rose Herbs in Oregon, because they are the cheapest that I've found.  You can get a pound for $25 plus shipping.  One ounce of the herb mixture will make 32 ounces of the tea.  If you take two ounces a day, it will last a couple of weeks, or if you use just an ounce a day it will last a month.  From what I've read, less is better.  A recommended dosage is 2 ounces a day (one in the morning, and one in the evening) for a week, then one ounce a day at bedtime for three weeks, then back to two ounces.  They suggest taking it on an empty stomach and some have had remarkable results with it.

Best to you in your quest for healing your father.