Electronics - receivers or ESCs - you might salvage if you can get all the water out.

Remove any heatshrink or labels, then wipe it with some Isopropanol, and leave it dry for a while, most boards which are "just" electronic won't be damaged by being briefly submerged.

Unfortunately anything which can't be dried out will be ruined, for example, if your receivers have a metal can on the pcb, the water won't be able to be cleaned out (you could try unsoldering the metal can to clean underneath)