Try concentrated SimpleGreen. This is a good ink-remover.
The foam pads are built never to come out although there are some intrepid you-tubers who have worked it out. It requires time and screw-drivers so this might not be your cup of tea. If you re-connect the lines and do another init-fill you should be good enough to print with but you may want to let the printer sit on a towel for a while. It’s built not to harm electronics even if the pads are saturated.
Did air get into the lines due to running carts totally dry or not priming the cartridges? Do you see air bubbles when you hold a flashlight against the lines (it’s a hard printer to verify air bubbles w/). Topping of the carts and running 1 init-fill or a series of nozzle cleanings will purge the air.
The R3000 is basically the same printer as the newer P600 (same printer and just a slightly updated head and more finicky paper loading on the P600.)