The password for the lab is in one of the WIP objects in DeeDee's room. In the lab, there's an in-progress love potion that seems to be completeable with household items (I'm currently working on seeing if this is doable). Peeking on her shower scene and scavenging random pics of her throughout the house allows for the bedroom scene.
You might have expected it, but saying "Your ass" when she asks what you'd like to eat in the kitchen isn't the appropriate response; that said, it doesn't immediately end your game either. The soap next to her seems to be useful for something (maybe the potion?), and starting to think the doll in DeeDee's room is also meant to be used for that. Only thing left is paprika and tobacco leaves.
e: Paprika's in the kitchen, after using the bathroom to jerk off and she's out of the kitchen. While she's out, clicking anything except the dishwashing liquid will allow searching (though it will recycle the "Huh, she's not here, where is she?" re-entrance) (speaking of, using the bathroom also recycles the first entrance of the house for some reason) Back to the subject; there's a pack of cigs in DeeDee's room as well, so that's probably where the tea leaves "would" come from. Only real thing left is Dexter's "special mix," and pretty sure that's hidden behind some secret passage involving the books and globe in the bookcase. If it's in the lab, there seems to be no hitbox for it (just for the love potion schematics, another book that says it has a picture (but no image), and the glasses. Speaking of, the X-ray glasses seem to freeze the game upon automatically attempting to use them in the kitchen.
Personally entirely fine with not mimicking the exact art style for her character.