If I use a gravel vac on an aquarium(6-20gal) will it mess up the gravel and soil layers?

If so, how do people with gravel/soil layers clean up the poo/fish food/dead leaves/etc off of the bottom of the tank?
A bit off topic- Oil Dri, Potting Soil(Top Soil?), and Fluorite, do they run out of nutrients to give the plants over time or is it a lifetime thing?

Is Fluorite a lot better for planted tanks than Oil Dri or Potting Soil(Top Soil?)? I saw Fluorite bags for 28$/bag but I'd rather not pay that much unless there's a noticeable difference between the substrates. (Pretty sure that online ordering will cost too much with shipping, in Hawaii)

How do those substrates rank? (Fluorite > Oil Dri > Top Soil etc)

Sorry for all the questions, thanks in advance

I don't gravel vac my soil-based planted tanks - the plant covering is too dense anyway.

I have Amano shrimps and Malaysian Trumpet snails to process the poop/fish food/dead leaves into mulm, which then feeds the plants.
Shrimp may present difficulties depending on the other tank occupants but MTS are practically indestructible.

Re: flourite vs Top soil (Sorry, I don't know what Oil Dri is)
It depends what you want to do with your tank.

If you are going to be aquascaping it every week or so, want deep aquascaped terraces, or are impatient, I'd go with the flourite (or any of the another "proper" substrates).
If you don't tend to fidget with aquascapes too much, or you're on a budget, or don't mind doing research/preparation, soil is perfectly ok.

Soil also allows you to get away without having to dose micros in lower-tech tanks most of the time (not sure flourite provides everything?).
In a high tech tank you'd most probably have to dose micros with either substrate.

Thanks a ton for the post, clears a lot up

you can vacuum a few inches above the substrate. Stir up the detritus and vaucuum.

In my soil/clay substrate tanks, pretty much all my tanks, I only have to dose K about 1 to 3 times a year if I start to see a deficiency. Everything else comes from the water changes, fish wastes, fish food, and the substrate. These are tanks of crypts and anubius mostly, I'm not into stem plants.

I don't vacuum the substrate, that would undo the whole point of the substrate. I do wave a hand in the water to stir up anything that is on top of the substrate during water changes.