Everybody is saying "WD40 is not a lubricant" but everyone seems to be missing the point.
I dont think anyone intends to open their reel up and spray WD40 inside. Instead, we are considering spraying a ton of it all over the OUTSIDE of the reel, so when the reel gets splashed with salt water while surf fishing, the WD40 displaces the water and hopefully the salt water foes not get in and corrode anything.
I bought a cheap $20 reel at Walmart and I am now experimenting with this. I spray it down very well with WD40 all over the outside and let that sit for a few minutes before I use it in the surf. We'll see if this reel lasts a long time as a result.