In the any% category, wallclips are a common problem for runners attempting to get times in the category. However, there are setups for many of the wallclips in the game.
Setup 1: On level 6 (after beating the level where you fight 4 red fish), buffer a down input along with a dash input. release the dash on the 2nd stage of dash strength whilst still holding down. buffer the inputs for another dash, and this time release it at the full strength to clip through the wall.
Setup 2 and 3: These setups are identical due to having the same initial level layout. The first is one Level 8, immediately after the arena fight with three pufferfish. you buffer a dash and down input again, but this time you release the dash at the lowest power, holding down the entire time, then you buffer a maximum strength dash to clip in. The same layout appears again in Level 14. Simply repeat the same buffer, and you will be able to swim downwards to that finish.
These are the three wallclips that have buffered dash setups.