Are you talking of the wipe on poly?
I sand to 240 grit mostly, sometimes 320 if I want a real shine.
You can buy wipe on poly by minwax if youre rich. Or you can just mix white spirit (thinners) with an OIL BASED poly in gloss, matt , or any other finish you want. I always use clear gloss. DO NOT try water based, it dont work
Malcolm (kentucky) on here helped me a lot in getting the mix right. He's been doing this way longer than me.
I use 5 teaspoons poly to 4 teaspoons thinners, but whatever works for you. That will do a large box inside and out, and if you cover it carefully it will still do a second coat the next day (doesnt soak up any where near as much on the second coat).
Wipe on with a small piece of clean rag or heavy duty paper towel. Wipe off excess with a new clean piece or rag or towel, dont scrub it clean, just enough so it doesnt go globby on the edges. Let it dry.
I then use OOOO wire wool very gently to de nib and coat again.
Do that as often as you want.
But you must let it fully dry before you even handle it let alone put more on or youll smudge the finish.
I use vinyl gloves so I dont put fingerprints on the wood while coating it.
The boxes I flock the insides. just as per instructions when you buy the stuff.
But I have found a dodge for that (dont tell anyone, will you?). I cant get the special glue here because its not sold on island and the stuff is flammable so it cant be air mailed. I have found a way round that using metal paint like Hammerite, but you have to match the paint colour to the flocking colour. But I have just found a way around that as well, because the metal paint was seeping through the thin wood of the drawers and colouring the external finish. I now just use ordinary white PVA glue. I put a large dollop in the middle of the box, quickly spread it evenly around the internals, and then flock with the applicator. The glue dries clear so I dont need to keep buying different colour paints because I have blue, black and red flocking powder. (SHHHHHH>)