I'll save you the bother. Normally what causes a plug to over heat is a bad connection in the plug itself. Check all the connections. Re-do them if needed by cutting the flex back to fresh shiney wire. Next common fault is an internal break in the flex usually where it enters the machine and has been stressed. The wire breaks inside one of the cables causing the current to jump the gap. This raises the amps leading to a strain on the plug and socket which causes the overheating.
Failing these there is probably a fault on one of the machine components.
Get it sorted, water and faulty electrics don't mix and it might not be you who gets hurt it could be your customer or worse still their child. Imagine how much crap that would bring down on you, its not worth it for the sake of a few quid. If you're busy make the time.