I use to drink a glass of water with a few tablespoons of vinegar before bed time to clear my sinuses and help with the constant sinus drainage I had back then when sleeping. I was already getting to sleep fast and sleeping good back then so I can't say if it helped with sleep. Other than it cleared my sinuses so I didn't have a throat full of thick snot. Might have even seemed to help with sinus inflammation. But it was a long time ago. And for certain all is circumstantial at best.

It didn't matter what type vinegar. Just as long as you could tolerate it. Apple had a little better flavor, white wine vinegar was a little milder and distilled white vinegar more stronger sensation and maybe nastier to some. But it all seemed to work the same.