Tomorrow is way too soon if you don't want it to experience kernel panics down the line.Pray for the best, and see what its like tomorrow.
Typical water contains many conductive elements. Turning it on quickly could short circuit something. That would be one of the reasons you don't clean the inside with water. If you had to redo thermal paste or something, you would use isopropyl.Water doesn't lead electricity.
Should be fine.