He would have to have the chivalrous streak of Wil, the personal insecurities of Marten, be OCD in similar ways and to similar degrees as Hanners herself, be a health nut like Raven... and have a vagina like TAI!
Okay, that last one wasn't (necessarily) serious.
I think he'd prolly have to be a Vegan. That, and an otherwise clean, pure, "organic" diet and impeccable health resumé evincing a powerful (read: clean) immune system. If for no other reason than her aversion to physical contact, Hannelore would be the kind of girl who likes to be wooed. Wooed hard, and for a long time, heh. Eventually, learning him to be as fastidious about cleanliness as she, Hanners might warm up to him, and her OCD defenses could come down to allow this uniquely qualified individual to touch her without catatonia setting in, and after that, more comfort around his bodily fluids: sweat, saliva. These things can and do work out.
OCD is a syndrome of opposites. Howard Hughes thought everyone else who bathed was filthy, even as he, himself never bathed and descended into decrepitude. Like an anorexic who sees her emaciated form and thinks herself fat, Hanners's OCD could look at everyone else as tainted, EXCEPT her perfect mate, because she knows him to be "clean" in the OCD sense of the word. He'd be like a stealth bomber of love, evading her OCD radar.
God only knows how she'd handle getting pregnant, though. "You mean there's a- whole `nother person inside me... pooing and peeing?" *catatonia sets in*