My big toe nail often 'extends' slightly at the sides where it touches the skin. This frequently becomes ''clogged'' with nail particulates (like in most people I'm sure), which requires removal by the blade end of a nail cutter, and cannot be removed by hand. While doing wudhu, it is possible that water may or may not reach the very bottom of this space, although it is likely. In that case, has the fardh component of washing ALL the feet in wudhu been achieved?
Also, sometimes cotton (from socks) gets stuck in the sides of my big toe, which again has to be removed with a nail cutter 'blade' and cannot be removed by hand. However, being cotton, I am confident that the water penetrates all the way through. In that case, can I assume that wudhu is valid?