Many times I use acrylic paint (artists' paints) for details after it was base coated with Drylok. Because you used exterior latex paint that would give it the same protection so you are good there. I've never had problem with the details paint effects washing away so you shouldn't be concerned. You are good to go :)
Not sure but if you strike out with Home Depot/Lowe's perhaps try Ace Hardware. They always seem to surprise me that they carry stuff I don't usually see at other places.
I like the water-proofing characteristics of Drylok because I'm usually adding in details of things that were dipped in monster mud so I need it to be waterproofed. The pink foam itself doesn't need to be waterproofed. It's that way on it's own. I love Drylok not only for the water-proofing though. That grit does give it...
Hee! Hate to be so basic about likes and dislikes but being very honest here: I would love anything homemade that shows off my reapee's love/art of making props/crafts. I guess the only dislike is gore.
You could try what I did with the Demon Horse. You dip cheesecloth into the Drylok. It helps reinforce the Drylok like if you were fiberglassing. I named it 'Cheeseclothing'. Here's the vid (Fast forward to time stamp 3:12):
I'll never forget when I stumbled upon this place. I was confused by my newfound intense passion for Halloween and didn't know where to share it. Then I found HalloweenForum and fell in love with everyone. Thanks Larry!