Back from the store with Melafix and Pimafix. Did lots of research, and yes I did read about the Bettafix... found this somewhere:
"MelaFix - MelaFix is 1.0% Melaleuca. It is the more concentrated, or stronger, of the two remedies.
BettaFix - BettaFix is 0.2% Melaleuca. It is less concentrated than Melafix, this means for every one drop of Melafix, you would need 5 drops of BettaFix to get the same amount of Melaleuca. "
From the instructions, Melafix uses 5mL per 10 gal, and Bettafix uses 2.5mL per gallon, or 25mL per 10 gal.
You can see that you end up with the same amount of Melaleuca, using 5 times as much Bettafix than Melafix.
I agree, don't understand why they say not to use Melafix on Bettas.
Thanks again for the advice, keep your fingers and fins crossed for my wee tetras.