TL;DR: See how much easier it is to get your security deposit back when you have your own portable carpet cleaner, like the AILLTOPD C4, which is on sale now for $89.99.
Moving apartments is the worst, but the allure of getting your security deposit back is the light at the end of a long tunnel. Except, you might not get it back if the place isn't spotless, and that includes the carpet you've been walking, spilling, and living on all this time. Hiring a professional carpet cleaner is the expensive option.