Clindamycin is not typically a PN trigger. It can affect bowel flora however majorly. Some people believe that altering the bowel flora significantly leads to other medical issues. But that is beyond the scope of our board for now.

The Parkinson's forum discusses bowel flora in relation to treating some symptoms of PD or as a trigger for PD developing. But still that is experimental today.

If you can get some Kefir where you are.... and eat some daily...you might see some improvement. Lifeway Kefir is making a mainstream appearance now. It has 12 probiotics in it, and is delicious as well. And affordable. Some of us use it here. It was very helpful for me over a year ago. Much better than yogurt, in fact.
http://www.lifeway.net/

I would explore those mechanical issues with your surfing stress on the feet. It can't be easy for them as we age, to do what you do. Try the ice treatments and stretches on the Northcoast footcare site that I gave you... I really like that site, and you might look around there further. I personally found lacing suggestions to take the pressure off my high instep...this simple solution stopped my numb toes!

Many foot problems can be traced to mechanical stressors which then affect the nerves. So the PN would be secondary to those stressors. (something you probably don't want to hear or would not like to know if you love your surfing.).