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.