Ethylene glycol will decompose, especially with heat ; Glycolic acid is mildly corrosive so I would prefer to clean it off if you can. I would go over the areas you moped it up from with some clean water. Just make sure you 100% dry everything after. Hair dryer on warm air setting or Airing cupboard and silica gel for a couple of days......
Did any get down into the socket? Or with the processor in place did you get lucky and just have some exterior "wetting".
Anyway...once bitten twice shy completely understandable. probably the main point is that these "closed loop" coolers are not infalible and leak testing with no power to board or components is probably recommended with them just as well as it is with your own WC loop.
Fingers crossed the board and CPU are OK!:)