One problem to consider is corrosion from entrapped water molecules. The best practice I am aware off is to sink the parts after testing in a barrel of water repellant oil. Otherwise you risk corrosion even if you dry the parts in an oven.
Most MPI ink suppliers will sell you water-based ink conditioners and post-test protectives to prevent corrosion of parts after MPI. I agree with israelkk, you'll need to immerse in dewatering oil afterwards
Nigel Armstrong
Lloyds Register
Independent Verification Body Surveyor
website. They have a great deal of product information. As israelkk and ndeguy mentioned there is definitely a trade-off going to a water based solution. In addition to anti-corrosion agents water based solutions also need a wetting agent and an anti-foaming agent. Luckily, you can buy the particles already containing all the necessary additives from most suppliers (like Magnaflux). The biggest caution I will give about water based solutions is that you must constantly monitor them. It doesn't take much of an imbalance to really throw things off. If properly maintained, water based solutions work quite well.
