Hello Braxton.
Yes that is a good idea.
But not a necessity....I didn't wash any of my models.
But then I didn't handle them to much.
The reason for washing sometimes is factory release agents on models.
But this is only ever on injection moulded plastic kits.
FFG models are assembled and painted
There fore would of been cleaned already.
But there is also the natural grease in the pause of your skin.
From your fingers.
But as I said.
Didn't wash my models.
And the varnish I use is Acrylic
So it doesn't react....with anything.
Just have to be careful with the temperature.
A warm environment will make sure the paint doesn't plume.....go a misty white.
Ideal temperature is above 20 degrees.
Paint molecules don't work very well below 15 degrees,
I'm a professional painter in my job, I spray in temperatures above 25 degrees, to make the resin set properly.
But you don't need that much heat.
Also. Thin spray coats. Don't go to heavy.
But most of all,Have fun.
all the best.
Barry.