Seal your base colour with a gloss, it’ll ensure your chipping comes off smooth and that you’re not having to rub so hard.
As with everything, ensure lots of cure time
for your gloss before your hairspray.
I’ve always used flat white, but no reason you can’t do gloss if you’re going to flat coat the whole final tank when you’re done.
If you’re using Tamiya, use their X-20A thinner or IPA. Water does weird things to Tamiya and it won’t spray. Lacquer/cellulose gives too hard a finish and it won’t chip nicely.
For added whitewash fun, AK makes a washable white paint that you can slather on after for a more drippy look.
I’ll send you a couple videos to watch too that helped me.