mantra affirmation

Practicing a MILD technique...

Is it wiser to every night repeat one mantra such as "the next time I dream, I will remember I am dreaming"

Or is it also ok to repeat 5 those kind of mantras a night, another example is "When I see a DC, he will tell me I am dreaming"

Will having more affirmations make things stronger? or will it mess up the mind, and is better to focus just on one?

am also wondering this... i have trouble staying with just one thing for too long. i have a feeling its all good as long as its all toward the same outcome.