I do 100% (or as close as I can get) daily for 2 weeks when I am setting up a new tank with Aquasoil. Otherwise nitrates will stay really high.
I would disadvise 100% water changes - mabe 50% or at the outside 75%. Otherwise it can disturb the bacteria. I would plant stem plants- they will take down the ammonia and thereby reduce the nitrate. Meanwhile the nitrifying bacteria will develop.