I recently got my hands on a valiha (an string instrument from Madagascar) which seems quite old, despite still working. I would have loved to change the strings since they seem a little bit old, but they appear to be nailed in place, so I can't safely remove and change them.
Therefore, I am trying to find a way to keep the strings as clean as possible. Would there be an efficient way to protect and/or clean the strings?
EDIT: As requested, some information about the valiha I have. First of all, a photo.
There are 17 strings, which are definitely nailed in place, I can't change them (good valihas have tuning pegs, not mine). It is a plucked string instrument. Here is another photo; it's a top view of the instrument that shows the nails piercing through it.