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Short version: No. It needs to be 95% or higher.
Longer version: Products with 6.49% (or 6.25%) are typically curing combinations either with Propylene Glycol and Sodium Bicarbonate, Red dye 3 or just with sodium chloride (table salt). None of those will be sufficient for CTB.
Even for argument sake if someone were to try it, as the amazing @LunarLight said someone would vomit long before any chance of it working. I am unaware of anyone being successful doing it that way, although I suppose anything is possible. But that would be 385g+ at that lower amound to feasibly get near 25g of SN (25g % 0.0649) which is almost a pound of it. I don't particularly see that as realistic or doable. Even then, not sure if someone would die but it sure sounds like a very unpleasant thing to try.
And no, there is not an easy or effective way to try to extract just the SN from those compounds to get a purer form (you didn't ask but could be a logical next question for someone asking this current question). For example, SN and sodium chloride (aka table salt) exhibit comparable chemical properties, particularly in terms of solubility, which complicates their effective separation using conventional techniques such as crystallization, ion exchange, or even filtration. Even if you had the technical knowhow it would be pretty complicated. These approaches would still be inadequate for achieving high-purity separations when the target compound is present in such low concentrations.
So sticking to 95% of purer of SN for the protocol and method would be the way to go if this is your prefered method to explore.
With whatever you decide, I hope you find everything you are looking for and get peace & serenity.