Sorry for the delayed responce, this message is down so far I didn't see it.
The milkwash and pickeling is so thin and since there is no wiping it off, it it easy to let it run, you almost have to drybrush it on, then it is difficult not to leave missed spots (holidays), the small holidays can be difficult to spot untill you apply your first finish coat then it shows up good and it's too late. There are pickeling products that claim to be easier but I have never used them, I mix my own.
The mixture I use is toxic (thinner based)until it is dry. Always read the label when painting.