I've taken tetracycline orally for several years and clandemicine (hope its spelled right) as a topical treatment - both were prescribed by dermatologists.
The topical one was better and I didn't have to worry about yeast infections.
As far as applying anything in the guise of a toner - make sure that the ingredients are small enough so that they can be absorbed into the skin, and the effective ingredients will have the opportunity to work.
There are too many over the counter (and natural products) that don't work because the active ingredients are too large and therefore not absorbed.