[Arran]

Yes, tri sodium phosphate, I don't know why I forgot to spell it out, it's available in every paint store, hardware store, and even places like Walmart.
It's pretty much like a strong soap, I've been using it for years with no real troubles, occasionally a rusty screw if it was an unplated screw and didn't dry quick enough. I would also recommend oiling the threads on any trimmer screws before and after the chassis gets washed and dried. For whatever reason I have never got around to posting any pictures on here, something I will have to figure out, so give it a try and show everyone how it came out.
Regards
Arran