Never known anyone with OCD?
I have. I've known a few, actually. Hanners doesn't often display OCD. She has it. I'm not saying she doesn't. She find counting things soothing, and has stated, obliquely, that she feels compelled to do so. That's pretty much the definition of OCD. An obsession level fixation on an act that one feels compelled to act on. I knew a guy who was constantly washing his hands. He had no particular compulsion to clean, nor did he have a phobia of germs or any kind of hypochondria. If he could ash his hands, he did it. Because that was his fixation. Knowing he could wash his hands, and not doing it was simply intolerable to him.
He didn't have crippling OCD. He could go hours without washing his hands. When he did wash them, he hardly took longer than anyone else might. But he did take longer, and he did do it more often than strictly necessary, or even comfortable for mere normals (Imagine the dry skin).
People with crippling OCD are compelled to the point that they need a massive effort of will not to act on the impulse to satisfy their compulsion (Like, "I must lock and unlock the door exactly 18 times in 25 seconds before leaving the house, Lose count or fail to meet the time, and I have to start over. I got it right this morning. Or I think I did. Maybe I should go home and make sure"). Or they suffer from so many compulsions that they don't have time for anything else.
Hannelore has a whole salad bar of disorders, though. She suffers from poor socialization, hyperawareness, difficulty focusing, hypochondria, poor impulse control,
extreme anxiety, obsessive thinking, and OCD. Just off the top of my head. If I had to grab a pop-culture diagnosis to explain her, I'd guess autism (high functioning) or ADHD. Frankly, I wouldn't try to capture her issues with one diagnosis. It wouldn't quite fit. For all of the issues she has, she really is well adjusted. For example, her lack of impulse control manifests in largely harmless ways. She knows, without need for external validation, that her violent impulses should not be indulged. She's internalized the label of "crazy," she she does wonder if she's the only person who has these kind of thoughts, but she doesn't act on them. She can be inappropriate (Stalking), but a lot of that can be chalked up to hyperawareness and obsessive thinking. She'll often allow those items to dictate her actions (Solving a social equation on the COD blackboard rather than starting her date with Sven, taking the opportunity to collect Martin's blood for a biomarker screening--having the equipment to do so on her person while at a social engagement). She generally doesn't let her hyperawareness lead her to say things that would discomfit her friends (one gets the impression that she knows a lot more about them than they probably think she does. She may know things they don't know). She's able to manage her hypochondria when necessary, and she's willing to question her anxieties, and listen to the points of view of people who don't share them.
I read her obsession with cleaning things are just that. It doesn't seem to be a compulsion. It's something that she genuinely enjoys. That's not the reason she does it, but it's not just "scratching an itch" either. Juicy's panties had a one-two punch. They ruined an otherwise soothing activity, and they triggered her hypochondria. Rationally, she would have to know that just aggressively cleaning her clothing would be enough. Rationally she'd have to know that her general mode of dress brings her into contact with more kinds of bacteria than she could possible have encountered because of someone else's underwear. But that's the calling card of a disorder. They tend not make sense.
So, tl;dr, I agree that rewashing couldn't have been enough, if the panties were a problem to begin with. I'm just putting in a word for all the folks with whatever level of OCD who wouldn't be bothered by them. Or who would have had to rewash everything, because the panties meant an even number of garments went through the second load (The second load has to be odd, to balance out the fact that 2 is an even number. Also, did you know that zero is an even number? I bet Hanners does). And so on.