You did the correct thing by removing the battery. Even when the laptop is off, there is always power available at various points on the motherboard. The power button is not a power isolating button. It merely signals the BIOS as to the user’s intentions. Think of the laptop as being in an extremely low power state rather than being totally disconnected from the power, when it is turned off.
Check the ingredients on the label of the keyboard cleaner and see what it states. Depending on what type of “additives” are included in the mixture with the alcohol may decide what residues are left on/in the laptop. Hopefully it is purpose designed and that there are no conductive residues left when it dries out. Time will tell I suppose.
If there are any problems after it has completely dried and you turn on the laptop, here’s the hardware maintenance manual for the laptop. On p.94 it details all the necessary pre-requisite steps and the procedure to remove the keyboard assembly. This should allow you to check the motherboard to see if the liquid (foam) passed through the keyboard and onto any components under it etc.
Also if there are any damaged components, here’s the parts list. Click on Select Commodity to find the part and the part numbers. Search online using the part number only to find suppliers. Hopefully you won’t find it necessary to do this.