I don't think sand does as good of a job cleaning the chins. Any time I've used anything other than blue cloud my chin's fur has still looked pretty greasy after dusting.
I have read somewhere thats this is a good sand, i dont think i have got this one before though but its not too pricey. I buy my sand from a local pet shop and the reason i havent changed is because its what they have always had, but my pet shop is shutting down so i think i will try this when mine has all gone, i also put a finer sand in with the one i buy which is off chinchillas2shop.
Sepiolite is used by breeders & the fine sepiolite is used before shows. I suspect that Blue Cloud is similar to the very fine sepiolite we use here in the UK.
Charlie Chinchilla dust is quite coarse IMHO & I would not use it.