I'm no programming expert, but I've played a handful of games that had these kind of disconnects and they were able to be clipped through.
I've tried this by myself for like 5 minutes with the following:
using a roller/paintbrush into it
kraken
squidding and jumping into it
climbing up the wall and try to slip thru
inkzooka and stand backwards
I might try swim/run speedups.
Though I think stuff like burst bombs, bubble/kraken/splash wall bumps any external form of knockback might allow for clipping.
If you wanna mess around with me my NNID is PHYTO-1
It's entirely possible that this can't be done.
And if it could I believe it will just result in instant death.