Jon, I've seen a few people paint the inside of their lenses with clear red paint, although DarkLyte subsequently replaced his with red acrylic versions. I'll do the same eventually but, for now, I intend to try the painting route.
I will airbrush mine with Tamiya Clear Red but what you have there is the same paint but in a spray can. The issue is going to be that the spraying will leave a 'texture' on the lens and so it won't be clear to see through. I have therefore done some experiements to help get some of the clarity back.
I'm using the old aircraft modeller's trick of using Johnson's Klear (known as Future in the US) acrylic floor polish. The technique is used to make an aircraft canopy clear again by dipping it in the polish and letting it dry. The Klear/Future fills the scratches and restores the clarity. I've done it myself many times with aircraft canopies and it works beautifully. You basically dip the canopy, wick off the excess and let it dry under a cover free of dust.
I experimented by first spraying Tamiya Red Clear on a piece of clear acrylic. That left it with a texture that meant you couldn't see through it very well. I then dipped it in Klear and let that dry. That went a long way to making it clear again so I think an extra couple of dippings should do the job pretty well. It'll never be as good as the replacement lenses DarkLyte used but it'll do for now.
That experiment was a while ago now. I'll repeat it before commiting my actual lenses though! I'll post some photos when I do.