After you beat Pryce (7th gym leader in Johto), you'll have to go to Goldenrod City's Underground Path, there is a guy there who will give you a Team Rocket Suit. Then, go the Radio Tower, and then, there you'll know what to do.
go to the seventh leader. -_-
Go to Goldenrod City and beat Team Rocket.
clainwood
ponie
get a pokemon, then you train it, get it really strong, and beat th ecrap out of all the 7th leader's pokemon. Its easy.
You have to beat team rockets warehouse in mahogony gift shop.
it is in mahogany town or if you already beat him probably chuck in cinnabar
Yes, beating the 7th Gym does not effect getting the secret potion.
the best way to beat the 7th gym leader is with a fire type Pokemon
you need a physic type
Water, dark and grass Pokemon
Go to mahogany town to beat pryce