Sammiejane, i will try the driclor oif all else fails.
Yeah i would say that it is better to try the other more gentle options first.
This tends to eliminate all 'sweating' for the first day or two and control for the rest of the week.
I am a particularly sweaty person (the type that would have to take a change of clothes or never lift their arms up due to the sweat patches) and now i can be more confident in most colours - even when lecturing for a whole day.

Its not an ideal solution - however is better than being smelly or damp all the time!