I am a CTA trained 5 element practitioner, so I can make total sense of your treatment and plan! You have to remember this man has been sabotaged to a certain extent, and it may well be inevitable that he retains a certain amount of excessive sweating.
CF treatment, as a constitutional approach, can and does make a huge difference but it may take some time to get optimal results. If he has been suffering with his condition for a while you both may need to be patient and let it do the job! It is tempting to want to force the pace but, it happens in it's own time in many cases.
I agree that heart should be treated but do Sp 6 and 9, with St 40, to resolve damp. Also consider some Lung work, as it controls sweating.
How is he drowning? Earth needs nourishing, so he may well be resisting some kind of offer by someone or something; he may be drowning or suffocating which may antagonise water (fear). Earth is controlled by Wood on the Ke cycle so perhaps some anger emotion testing is called for?
5 element practice is mysterious as well as pragmatic - I have been doing it 11 years and am still surprised by what I find. My husband is 25 years into it (a JR student) and he says the same. Holding faith in your practice lets your patient hold faith in himself; between you, you will find a balance that gives you both some satisfaction.
6 treatments is nothing. You have achieved remarkable results in that short space of time. You most certainly have done more than those highly-trained (and highly-paid) doctors have!! Keep to the 5 element protocol, be mindful of other techniques, and you won't go wrong.