Most spring eyes, if they don't have wet bolts to grease them with, employ nylon bushings (very thin sleeves) that wear very fast.
It isn't hard to change them, but any spray grease would help for a while.
If you jack the trailer up a little from the rear, the leaves will separate a bit and you can shoot some grease between them also.
The last 3" of each spring is the part that needs the lubrication.
While you are doing all this, it is wise to closely inspect the bolts and shackles, especially the inside surface of the shackles, and spring eyes as when the lube dries up, or nylon wears out, metal on metal wear occurs quickly. I've seen spring eyes and bolts and shackles half or more worn through from friction.
Waiting for "someday" will leave you on your deathbed wondering why you didn't just rearrange your priorities and enjoy the time you had, instead of waiting for a "better" time to come along...
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