Spearmint Sprout, JUST ANOTHER FRAUDULANT SCHEME.

The sprouts would be exactly as usable as the leaves because they are the same plant only in a less mature state. They're likely less flavourful since the volatile oils would be less concentrated than in older leaves. Of course you could make them into tea if you wanted to. But you'd get a lot more cups of tea from a mature plant, which will return year after year, than constantly having to start seeds from scratch. It seems a pointless exercise to me.