As to cleaning for the loom and the ECU, isopropyl alcohol is usually pretty easy to obtain (Maplins). It will effectively flush oils and residue from the wires and is also totally non-conductive and fast drying. When I did mine I used first WD40 to thin the oil in the wire and the plug and also to drive out any moisture in the loom then used liberal amounts of isopropyl, worked a treat.