First of all, before I forget. I'd like the full version of this photo. The vivid hues... this looks like a glam shot, and I'd like the full version :3

This piece makes me wonder. Could he teach you how to let him go? If he's still got his hooks in you, then why will he be capable of teaching you how to let go? This makes me think that this wish is one born out of a misunderstanding.
Because the one spoken to never let go. What he can teach is how to appear as if one doesn't care.

I mean, it could be that this longing and holding onto is one-sided, but since this person has had quite a few pieces dedicated to them, then I don't think it's true.

Also, this "fear of contamination" is the fear of attachment. The fear of being hued or touched by someone else.
Learning to let go is one thing, but it's possible that all this other person could teach you is how to be closed. And being closed is not the same as letting a particular person go - it's binary, an all or nothing affair.

And if you close yourself to the world, you end up closing yourself to yourself as well.
Can't get "contaminated," can't, as you put it here, get dirt under your nails.
Can't get patina to cover you.
Can't let hurt in, but also not love.
And thus, you block out art, and life, and everything that makes life worth living.

And if we speak of it, then so many poems of washing your hands clean of this person. Of more than one. And yet, it is because it's not easy to let go. Of others. Of ourselves we see in them, and of ourselves we used to be, and of the current selves they taught us to be, even if with rods and scorpions, and lashes and blood.

And as you know, it's all a lie anyway. "Wear" is another way to speak of contamination, of patina, that comes from within. We can't keep the world out.
Especially not when we put so much dirt out there, on other people.

And this person, they don't let go. Not of anything.
If anything, it's you that needs to teach them, how to let go of themselves, and rebuild themselves.
Which is another topic you keep returning to. One that seems to hew closer to reality, rather than to the wish of the easy life. Those that take rarely give, let alone give in, about giving up on others, whom they have their manicured claws in.