clean pucker?

[Tan Cheng Ann <BA2319140@xxxxxxxxxxxxxxxx>]

hi guys...hope you can bear with another beginner's question.
i am still having problems with getting a *single* clean tone...
blow or draw. there is a lot of leak and no matter how much i narrow
my lips, i get some air over the other holes. when i narrow my lips too much, 
i can't get a nice tone (the air being too focused causes a sharp and thin
tone). are wood combs more prompt to leakage ? or is it just my lousy
playing? i just had more than an hour of practice..it was great.
i seldom have chances like this. my roomate is not around. he went
for a show...so it's practice time! some of you guys practise in cars
or when your wives are out buying groceries...what do you
guys do to *steal* as much practice time as possible? i have evn tried
playing with a blanket wrapped aroung my harp!!! ideas?
well..hope you guys can help me out with the leaky playing too.

-cheng ann
*still with one harp only...saving for another one*