Re: castor oil
I've read of lots of folks pulling with castor oil. It's supposed to be really powerful, one of the best. The most complaints I've read about it are the taste and thickness. Some folks can't "stomach" swishing the thicker oils and the gag reflex kicks in.
Re: amount of pulling
I think each person is different, and it also depends on what results you want. In general, the less toxic you are, the more pulling for results. However, some folks with more health issues need more pulling, like in my case.
In my own case, one 15 minute pull a day is only enough to clean the mouth and keep the keratosis pilaris (KP) at status quo. Three pulls a week total or less, and I see a regression of the KP. If I can manage 3 pulls a day (I usually do 15-20 minutes), the KP improves and goes away. My theory on the KP is that it's the essential fatty acids from the oils that manage to be absorbed while doing the pulls that is helping the KP, so the lesser number of pulls isn't getting enough of the omega oils into the blood stream. More is needed for status quo, and more to see the bumps go away totally. I've been experimenting with other things to see what makes the red dots fade that remain after the bumps go (trying Iodine and vit. E painted on ... Iodine alone doesn't seem to do it, vit. E helps, but the combination of Lugol's and vit. E do even better).
As for other general health benefits, again, in my case I need the 3 or more pulls a day. But I've a lot of unexplained health issues (despite doctors saying I appear healthy), things that docs can't really measure much, like fatigue, chronic sleep problems they can't diagnose, pain, etc. An average person without my long list of symptoms may see benefits with less pulls. For me the magic number is 3. After 3 pulls in a day any extra I get really great results (thick almost immediately, and doesn't thin until 10-15 minutes after). I try to do back-to-back when I can, because it's easier blocking of one block of time instead of several ... family has a bad habit of talking to me when my mouth is full.
Since you're pretty well detoxed from having been on Iodine for a long time, you may need more pulls to see results. I guess it really depends on what results you expect. If it's just general mouth health, one pull will be enough for you. If it's KP, you will need more. If there's additional health issues, more may be necessary, too. If you want speedier results, more frequent pulling is needed.