NO! Do not do this.
A couple of things, what type of paint? How long is the medium being left to dry? How are you applying the medium?
Generally speaking, it is best to apply the medium over a flat coat of paint. Also, the medium will come of pretty easy, you need to use a gentle touch to take it off, not a scrubbing motion.
A.
Automatically Appended Next Post: Here is a tutorial I did over on the Privateer Press forums about using chipping fluid, I am using AK Interactive(which is no longer available) but the Vallejo stuff is AK stuff re-branded. Take a look;
http://privateerpressforums.com/showthread.php?116134-Heavy-Paint-Chipping-Tutorial