Mr.BishopThere is actually more logic to this than you'd think.
Electronics are fine with water by nature... unless there is electricity running through them. That is why if your phone gets wet you're just supposed to leave it drying for a week and then turn it back on. (Bonus points for drying it with all kinds of those silica gel packets).
If there's no batteries, and no electricity in it... it just might survive this as long as its dried out completely before you plug it back in.
Def could be long term damage, and who knows maybe it'd just fuck it up outright (def dont' use soap). However as LE.Skiing said... fuck it you're no worse off if its already screwed.
Bishop wins for solid science.
I'll add a couple of things.
Before washing it take it apart as much as possible. keys off, everything off. Keep the usb out the water. reassemble after drying.
You can get big silica gel packets on amazon, cheap and well worth it.
After dishwasher-ing it rinse it thoroughly with deionised water, you can buy it at pretty much any hardware store. It doesn't (shouldn't) conduct electricity, so won't short the electronics like the water from the dishwasher will. Also dishwasher water will leave residue, deionised won't.