twigs in fmf pipe

Or an Easy way , Compressed Air from a Compressor , You will want to do it to both sides but It should do the trick if your worried about burning it or putting water in it .
 
Compressed air ftw.

When i got my blaster, the pipe was so full of mouse nest 135psi couldn't make it through
 
Coat hanger to remove all the material then high pressure water will clean it out good followed by a blow job from the air compressor!