The time it would take to carefully coat each bolt with Vaseline or some easy to remove coating would likely take longer than just painting them, them backing them out and stripping the paint off (with a wire wheel in a dremel tool, or just solvent and a rag)
I'd likely remove each, one at a time ....then replacing, after polishing the heads to a mirror finish. Just chuck the bolt in a drill and use a pad with a fine metal polish. That against the black cases would look awesome
I agree with KM.....then clearcoat or clear finger nail polish to prevent future rust.
Since May 2011
86 VN750 13,700 mi -Stock -Purchased 2008 w/8800mi
Replaced ALL Cables . Kuryakyn LED Voltmeter
Jardine Fwd Controls,
Custom Fenders w/Rails
Iridiums DPR7EIX-9 & Wires, Tuxedo Mod, Coil Mod, P/U Sensor Mod, Fork Seals,
Splines Lubed - 11/4/2012 - MF AGM Battery, Dampers went out @ 13+K !
After TOC MCCT's..... so amazingly quiet I discovered a rattling heat shield on my stock exhaust !
...have a Vulcan good day !