^White vinegar would be best. If you have freebase it will convert it to aMT acetate and dissolve it, it's cheap and convenient, it's distilled and sterile, and the acid content will keep anything from growing in it. It'll taste kind of gross, but you can always mix it into a larger drink or squirt it into capsules with a syringe if that's a big issue (though swallow quickly because vinegar will dissolve the capsules). If you're going to inject it I'd dilute 5 percent acetic acid vinegar by at least doubling the volume to reduce the sting. I've done this in the past with synthetic DMT using preservative free contact lens hot wash saline, which is basically sterile water you can buy at a convenience store.