Security is thorough but polite, courteously asking if Duo minds having his knife peace-bonded. They're used to weapons around here, Duo sees plenty of swords hanging from belts.

They assure him the spray they use won't have any negative effect on the finish of his knife or sheath, and they can apply the solvent on their way out.

Good enough for him, he doesn't expect to need to use it. And if he does, he can get creative.