What does Charles Bukowski believe the poem "Splash" can do for us?
I believe that what Bukowski is saying in his poem "Splash" is that there is life in the words, and not just words on the paper.
He defies the method of other poets to simply write ideas on a page: this kind of poetry, Bukowski says, is boring, and so he turns the tables and announces that what he writes cannot possibly be poetry.
The idea is that this "poem" goes beyond simple poetry as it wraps the reader in its words and transports the reader to a place where the rules don't count, or there are no rules. The ideas may be placed on a page, but the poetry is born and exists within the reader based upon how the reader interprets the work.
Bukowski challenges the reader to try and NOT to be affected by this poem. He draws the reader into the circle of words with phrases that evoke images and demand consideration, even if complete understanding of each image is difficult to grasp. I would guess that the poet is not so concerned that the reader get it all, but simple that the reader gives the poem a chance to speak in some—or any—way to its audience.
At the end, the poet says that the reader can die now with a true knowledge: of what? This is a good question. It must (has to) depend on the reader's perceptions, as everything in poetry (and the world) does! The poet believes that if you free yourself of the sense that poetry is flat—just a jumble of words—that you truly understand the beauty a poet creates——without the restrictions of someone else's belief (or perhaps even your own) that the words MUST mean one thing, and that if you don't get IT, it is meaningless. "Meaning one thing:" this is NOT true of art: it speaks many languages, and creates many pictures: and all may be different because it is based on the collection of personal experiences each member of "the audience" brings with him or her to the specific piece of "art," whatever its form: poem, painting, song, etc.
I would like to believe that the victory Bukowksi speaks of comes from meeting poetry on your own terms and taking from it what is says specifically to you, which does not need to be the same as what it says to others. It is a personal experience, and the sooner readers understand this, the more poetry speaks to them, and the less it is about reaching some impossible plateau where all is clear. If so much in life makes us ask thousands of questions, why would poetry be any different?
Bottom line: I believe the poet wants us as readers to do just what the title alludes to: it's about just jumping in, getting wet, and seeing what happens.
(Please remember that poetry speaks to everyone differently: it is the nature of poetry—any form of art—to do just that.)
Hope this is of some help.