Plastic recorders can be a real pain for getting 'fogged up' quickly - wooden ones in general aren't nearly so bad.
You can buy anti-condensing stuff in some music shops, which you then dribble carefully down the windway. Or if you put a little washing-up liquid in a bowl with water and then immerse the head-joint for a while, that should help - it makes the condensation form a sheen rather than big droplets, apparently. Don't put too much washing-up liquid in though, or you'll end up frothing rather than playing

!
But you'll never get rid of the problem completely; it's just something we have to deal with. 'Sucking back' during rests is the most efficient way of clearing the windway quickly and relatively quietly.