I am glad you like the idea, I do it and I try to convince all of my family members to also :-)
I would take at least 2 dropperfulls (2 ML), in water and OR under the tongue.
A while back during a very stressful time of my life, I would occasionally get some pretty severe chest pain, which I felt was due to stress.
Immediately when I got the chest pain, I got up as best I could and I would go for the cayenne, since I was home at the time, I took 1.5 ML in a glass of warm water, and within less than a 1/2 minute the pain was completely gone.
It actually felt like the area where my heart is, was cold. It amazed me how quickly it worked and how much I benefited.
And, it had shook me up having that much chest pain, and so the cayenne also relaxed me.
When my muscles are sore, or when I am under stress or need to relax, cayenne really helps.
I gave some to a girlfriend of mine when she was having major problems, in less than 5 minutes she was almost falling asleep, it relaxed her so much :-) Plus, she is a very tiny woman so it didn't take much for her.
I feel if a person conditions their thinking so that they know to grab the cayenne when they need it, they will.
Or if someone uses it once in a while, they are more apt to remember it is there.
It took me having to remind my mother when she needed it, and now she automatically does.
She has actually been saved during a heart attack because of the cayenne, and, it is always better to be safe than sorry.
If you feel you need some cayenne, take it, don't worry about taking it when not needed, you can use it all the time and as much as you would like, it is food and really is not going to harm you, just take it away from medications.
It sounds like your son-in-law could really benefit from changing his diet; it is too bad that he prefers to keep up with what he is doing despite the chest pain etc.
It definitely should be able to help reduce that pain, and also strengthen the heart, as Cayenne does that.
It strengthens the entire circulatory system, it also cleanses the arteries...besides balancing blood pressure, so, over time and consistent use, as with anything, it assists the body in functioning better, but, he really needs to also do his part if he wants to see real improvement, or the least, be able to control his present symptoms.
It is sad when some people have to wait till major problems happen before they decide to make any changes, and hopefully that will not be the case with him, even though it sounds like it is getting even more serious. Unfortunately some still do not make the changes once it gets to that point either.
And, of course you can't make someone do something they really don't want to do.
One thing I have learned is, once a person starts to eat better, and consistently stays that way for a while so the body has had time to adjust, the body then rejects the bad stuff once it is reintroduced, you will either vomit or feel like you have to, or other symptoms of rejection, and therefore not desire it any longer.
Hope this helps~
Take care :-)