Hi Phil,
I should imagine that three times a day would be fine. When I used it, I did not try to get it inside, but rather stuck to using it on the outside. This worked fine for me.
Diltiazem is a calcium channel blocker and usually does not cause headaches. Personally I feel that if you have had your fissure for three years it will be difficult to heal with Diltiazam. It is usually prescribed for acute rather than chronic AFs.
I imagine that what they use in Germany is Standardized Anal Dilation (S.A.D.) which worked well for one of our moderators (wecc). He had this done in NY, with great success. This is the link to his description of his recovery. Also, I am giving you a second link, to self-dilation, which a few of us have used:
my-standardized-anal-dilatation-this-morning-t4104.htmlself-dilation-t4261.htmlFeel free to ask any more questions you might have!