I would advise giving up on it at this point. Any opportunity to save it evaporated (so to speak) months ago.
For future reference, dealing with a spill:
Turn it off, but leave it open.
Turn it upside down, rotating the display toward you so that any liquid runs away from the display. From this point on in the procedure, leave it upside down and work on it in that position. Gravity is your friend and will keep the liquid from getting any further down into your iBook if you leave it upside down.
Unplug it from the adapter.
With a clean lint-free cloth or paper towel, gently blot (don't rub) away any visible liquid. Leaving it open and upside down, allow to sit and air dry (no fans or hair dryers) for another three days before reassembling it and trying to use it.
Never try to use a laptop that has been spilled on before disassembling and drying it out. Doing so can allow the liquid to come in contact with circuit boards and permanently short them out.
If, after allowing to dry for several days, the display does not work right, try reviving it by resetting the NVRAM and PRAM in Open Firmware:
- Start up into Open Firmware by pressing and holding the Command-Option-O-F key combination during startup.
- At the Open Firmware prompt, type: reset-nvram
- Press Return.
- When prompted for your password, enter it and press the Return key.
- It responds OK.
- At the Open Firmware prompt, type: reset-all
- Press Return.
The computer restarts (hopefully).
You can try the Open Firmware NVRAM and PRAM reset. If it won't start up in Open Firmware, I fear it's a goner.