If you’re talking about the possiblity of some titanic Jules Verne battle between a cephalopod and a tape worm in the GI tract, we need to reconsider the concept of swallowing a web cam and a flashlight…
It can assist the pushing from the inside. Unless we get a fun looking starship, miniaturize it and take a group trip along with the octopus and help.
You sci-fi writers should be taking notes riiiiight about now.
Reading this thread, I’ve been wondering what would happen if you started with something like those linked above. It’d be easier to swallow, given that they’re pill shaped to begin with 
Try it in suppository form first. Cartman did it.
i had something like this when i was a kid. as i recall, i had a turtle and a dolphin. when i got bored of watching it grow and shrink, i experimented. coke dissolves them into easily excretable slime, as does vinegar. so the pop rocks/coke/octopus plan might be the way to go. i imagine the pop rocks would help out too.