I don't know of anything safe to spray on it. From your description, it doesn't sound like the damaged area is exposed to the gliders. I wouldn't worry about it if that's the case right now.
A glider diner like Nightcat suggested can cut down on the mess. Some people love using them.
I recommend using a silo for water instead of a bottle. They never drip, they never malfunction, and they're easier to clean! I really dislike water bottles now since trying a silo and only use a bottle if absolutely have to.
I love
these
in small size. I've even at times served their nectar in them.
Also love to use
these
, currently I'm using one for their nectar (CLO). But I've used these for f/v salads, water and even for a few pellets at one time, but I've gone back to forage toys for those.
You can get both most likely at Petco or Petsmart in the store, but for some reason Petco doesn't sell the the cups on their website.