Treating IRS

[steviepip]

I have recently removed my IRS cage to carry out some remedial works including replacing shock/springs and break calipers.
I have also taken the oppurtunity to check for any rust problems. I have treated some areas for surface rust and propose painting where possible but for the areas that can't be painted (or can't reach) what can I use in spray form to coat these parts?

Cheers