Nope there isn't, just use those for battles against Emerald and Ruby weapon that's all you need em for.
use weapons with either double or triple growth, go into the crater (if you're there yet <img src="/images/graemlins/tongue.gif" alt="" /> which I assume) and throw some elixers or whatever them pots ask for whom you encounter there.
And they'll give loads of AP that shud help you lvl up your materia until you off course have the all mighty master materia
