These products that "smooth and condition" wine are usually liquid oak and glycerine. Sometimes conditioner is also nothing more than liquid sugar with sorbate in it.
to my tastebuds, liquid oak is aweful.
to my tastebuds, glycerine is good for about 2-4 months, after that, I think it ruins the wine so much I would not even cook with it.
And if it's sugar, well, I'm not sure that a sweet cabernet is what I'd choose.
Time will make it smooth.